JP2013225827A - Amplifier, radio communication device, and load changer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new load changer.SOLUTION: An amplification circuit comprises: an amplifier for amplifying a signal; and a load changer 5001 connecting to an output side of the amplifier. The load changer 5001 comprises: a plurality of transmission lines 5011, 5012 connected in parallel; and a first shunt circuit 5030 connected to some midpoint of one or more of a plurality of the transmission lines connected in parallel. One or more of a plurality of control elements 5021 in which an element condition is changed due to a control signal, is provided. The first shunt circuit 5030 comprises a control element 5021 in which an element condition is changed due to a control signal. The control element 5021 changes an impedance of the load changer 5001 due to a change of the element condition.

Description

  The present invention relates to an amplification device, a wireless communication device, and a load variator.

  Reducing peak power is one of the important technologies in increasing the efficiency of power amplifiers. In the case of performing broadband transmission, W-CDMA and OFDM are introduced as modulation schemes, and these signals have a feature of a large average power to peak power ratio.

For this reason, when these signals are amplified by a power amplifier, they must be amplified linearly even at the moment when the peak power that occurs rarely is output, and a high-power amplifier capable of outputting peak power is required. Become.
Therefore, when the ratio of the average power and the peak power is large, an extremely large amplifier is required, resulting in a very wasteful and low power efficiency device.

Therefore, a method of operating the amplifier by a necessary amount according to the output power is effective. One method for this is a power supply modulation method (Supply Modulation: SM method) such as an ET method or an EER method.
As another method, as shown in Non-Patent Document 1, there is a method for changing load impedance (Load Modulation: LM method).

  The former SM system changes the output power by changing the power supply voltage of the amplifier. On the other hand, the latter LM method is a method in which a constant voltage is applied to the power supply of the amplifier, but the output power is changed by changing the load impedance connected to the output side of the amplifier.

Hossein Mashad Nemati et al., "Evaluation of a GaN HEMT Transistor for Load- and Supply-Modulation Applications Using Intrinsic Waveform Measurements", IEEE MTT-S IMS, May 2010

The LM method requires a load variator that varies the load on the output side of the amplifier. Also, the load variator is required in various situations where high frequency signals are handled.
The inventors of the present invention have newly found a load variator that can vary the load with a different idea from the conventional one.
Accordingly, an object of the present invention is to provide a novel amplifying device, wireless communication device, and load variator.

(1) The present invention as seen from a certain viewpoint is an amplifying apparatus including an amplifier that amplifies a signal and a load changing unit connected to an output side of the amplifier, and the load changing unit is connected in parallel A plurality of transmission lines, and a first shunt circuit connected in the middle of one or more of the plurality of transmission lines connected in parallel, the element state of the first shunt circuit being controlled by a control signal The amplifying apparatus includes a control element that changes, and the control element changes an impedance of the load changing unit according to a change in an element state.

  According to the present invention, it is possible to change the impedance of the load changing unit according to the change in the element state of the control element.

(2) The amplification device is a load modulation system, and an amplitude variation is generated in an output signal of the amplifier by controlling an element state of the control element by a control signal based on an amplitude of an input signal of the amplification device. It is preferable to provide a load control unit to be operated. In this case, the load of the load changing unit can be controlled according to the amplitude of the input signal.

(3) It is preferable that the first shunt circuit is configured such that the reactance of the first shunt circuit changes according to a change in an element state of the control element. In this case, the reactance of the first shunt circuit can be changed by changing the element state of the control element.

(4) The reactance of the first shunt circuit is preferably inductive reactance. In this case, the inductive reactance of the first shunt circuit can be changed by changing the element state of the control element.

(5) It is preferable that two or more first shunt circuits are provided, and the first shunt circuit is provided in the middle of each of two or more transmission lines among a plurality of transmission lines connected in parallel. In this case, it is easier to widen the variable range of the impedance of the load changing unit than when only one first shunt circuit is provided.

(6) The number of parallel connections of the transmission lines is preferably two. While making it easy to widen the variable range of the impedance of the load changing section by making the number of parallel connections of the transmission lines, it is possible to suppress an increase in circuit scale by suppressing the number of parallel connections of the transmission lines to 2.

(7) A second shunt circuit that includes an element whose element state does not change but does not include the control element is further provided, and one of a plurality of transmission lines connected in parallel other than the transmission line provided with the first shunt circuit. The second shunt circuit may be provided in the middle of the above transmission line. In this case, the variable range of the impedance of the load changing unit can be changed by the second shunt circuit.

(8) The reactance of the second shunt circuit is preferably inductive reactance. In this case, inductive reactance can be given to the transmission line by the second shunt circuit.

(9) It is preferable that the control element discretely changes the impedance of the load changing unit. In this case, the impedance of the load changing unit changes discretely.

(10) It is preferable that the control element is a switching element that is switched between a conductive state and a non-conductive state by a control signal. In this case, it is possible to change the impedance of the load changing portion according to switching between the conductive state / non-conductive state of the switching element.

(11) It is preferable to further include an additional element that constitutes a resonance circuit together with the switching element. In this case, the switching element can be brought into a more complete conduction state or non-conduction state.

(12) The first shunt circuit preferably includes a plurality of the switching elements. In this case, the impedance of the load changing part can be changed to a value of 3 or more.

(13) The control element is preferably a high-frequency switching element. In this case, switching can be performed at high speed.

(14) The control element is preferably a PIN diode. In this case, switching can be performed at high speed.

(15) It is preferable that the control element is connected between a midway position of the transmission line and a ground.

(16) It is preferable that the control elements are connected in series so as to be interposed in the middle position of the transmission line.

(17) The transmission line is preferably a λ / 4 transmission line (λ is a signal wavelength).

(18) The control element is preferably connected to a position where a line length from the end of the λ / 4 transmission line to which the control element is connected is λ / 8.

(19) It is preferable that the control element continuously changes the impedance of the load changing unit. In this case, the impedance of the load changing part changes continuously.

(20) Each of the plurality of transmission lines connected in parallel is a λ / 4 transmission line (λ is a signal wavelength), and the overall characteristic impedance of the plurality of transmission lines connected in parallel is calculated from the load changing unit. The output signal is preferably a value that does not match the impedance of the circuit to which it is applied. In this case, the variable range of the impedance of the load changing unit is appropriate in relation to the amplifier.

(21) The overall characteristic impedance of the plurality of transmission lines connected in parallel is preferably smaller than the characteristic impedance of the circuit to which the signal output from the load changing unit is applied. In this case, the variable range of the impedance of the load changing unit is appropriate in relation to the amplifier.

(22) Each of the plurality of transmission lines connected in parallel may be set to a line length other than λ / 4 (λ is a signal wavelength). In this case, restrictions on the line length of the transmission line are reduced.

(23) The first shunt circuit includes a switching element as the control element. When the switching element is in a conductive state, (λ / 2) × n (λ is a signal wavelength; n is 1 or more. When the switching element is in a non-conductive state, the stub has a predetermined line length (hereinafter referred to as “non-conductive state line length”) for changing the impedance of the load changing portion. It is preferable that it is comprised so that. In this case, in the conductive state of the switching element, the current flowing through the switching element is reduced, and the loss can be reduced.

(24) the non-conductive state line length is taken as D _L, from the first shunt circuit is connected to the middle of the connection position of the parallel-connected plurality of transmission lines, line line length is D _L And a second stub having a line length of λ / 4 connected to the first stub through the switching element, and the second stub is connected to the first stub through the switching element. One stub is preferably connected to a position λ / 4 from the connection position. In this case, in the conductive state of the switching element, the current flowing through the switching element is reduced, and the loss can be reduced.

(25) the non-conductive state line length is taken as D _L, the first shunt circuit is connected to the middle of the connection position of the parallel-connected plurality of transmission lines consists of lines line length is L It is preferable to include a first stub and a second stub having a length of ((λ / 2) −L) connected in series to the first stub through the switching element. In this case, in the conductive state of the switching element, the current flowing through the switching element is reduced, and the loss can be reduced.

(26) the non-conductive state line length is taken as _{D L,} it is preferably _{λ / 8 ≦ D L ≦ 3λ} / 8.

(27) An auxiliary impedance converter provided between the amplifier and the load changing unit is further provided, and the auxiliary impedance converting unit matches impedance of the load changing unit viewed from the amplifier with the amplifier. It is preferable to perform impedance conversion so as to fluctuate in a range higher than the impedance. In this case, the impedance can be varied in a higher range.

(28) It is preferable that the load changing unit includes a plurality of partial load changing units including a plurality of transmission lines connected in parallel. Since the load changing unit includes a plurality of partial load changing units, it is easy to realize various impedances.

(29) It is preferable that the plurality of partial load fluctuation portions are cascade-connected in series. In this case, a load variation unit in which the partial load variation units are cascade-connected is obtained.

(30) It is preferable that the plurality of partial load changing portions are provided so that the respective partial load changing portions are alternately arranged on the front and back surfaces of the double-sided board on which the circuit patterns are formed on both the front and back surfaces. In this case, it is possible to prevent an increase in the size of the load fluctuation portion while avoiding interference between the partial load fluctuation portions.

(31) It is preferable that the load changing unit further includes an isolator that passes signals output from the plurality of transmission lines connected in parallel. In this case, it is possible to remove the influence of fluctuations in the output impedance of the load fluctuation unit.

(32) The present invention from another viewpoint is a wireless communication apparatus that includes the amplifying apparatus according to any one of (1) to (31) and amplifies a communication signal by the amplifying apparatus. .

(33) The present invention from another viewpoint includes a plurality of transmission lines connected in parallel, a first shunt circuit connected in the middle of one or more transmission lines among the plurality of transmission lines connected in parallel, The first shunt circuit includes a control element whose element state changes according to a control signal, and the control element changes the impedance of the load variator according to the change of the element state. It is.

1 is a circuit diagram of an amplifying device according to a first embodiment. It is an efficiency characteristic figure. It is a circuit diagram of the amplifying device which concerns on 2nd Embodiment. It is a circuit diagram of the amplifying device concerning a 3rd embodiment. It is IQ top view of an input signal and an output signal. It is a characteristic view of the load with respect to input electric power. It is a characteristic view of the load with respect to input electric power. It is a circuit diagram (the 1st example) of the amplification device concerning a 4th embodiment. (A) is a table showing the relationship between input power, load, output power, and gain, and (b) is an input / output characteristic diagram. It is a circuit diagram (the 2nd example) of the amplification device concerning a 4th embodiment. It is a circuit diagram (the 1st example) of the amplification device concerning a 5th embodiment. It is the relationship table of the input electric power and load which were set to the load control part. It is a circuit diagram (the 2nd example) of the amplification device concerning a 5th embodiment. It is a circuit diagram of a load variation unit using signal synthesis. It is a circuit diagram which shows the 1st example of the amplifier which has a load fluctuation | variation part using a signal synthesis | combination. It is a circuit diagram which shows the 2nd example of the amplifier which has a load fluctuation | variation part using a signal synthesis | combination. It is a circuit diagram which shows the 3rd example of the amplifier which has a load fluctuation | variation part using signal composition. It is a circuit diagram which shows the 4th example of the amplifier which has a load fluctuation | variation part using a signal synthesis | combination. 1 is a circuit diagram of a LINC type amplification device. FIG. It is a circuit diagram of the load fluctuation | variation part using a variable phase shifter. It is a Smith chart which shows the impedance fluctuation range in a load fluctuation part. (A) is a graph which shows the relationship between the change of a voltage difference, and reflected power, (b) is a graph which shows the relationship between the change of a voltage difference, and passage electric power. It is a circuit diagram of the load fluctuation | variation part using a variable phase shifter. It is a circuit diagram of the load fluctuation | variation part using a variable phase shifter. It is a circuit diagram of the amplifier which has a load fluctuation | variation part using a variable phase shifter. It is explanatory drawing which shows the relationship between the load fluctuation range of a load fluctuation part, and the load fluctuation range seen from the amplifier. It is a figure which shows the example of a circuit structure of variable impedance. It is a figure which shows the measurement result of a loss rate. It is a measurement result which shows the relationship between the impedance of a distributed constant line, and a loss rate. It is a circuit diagram of the load fluctuation | variation part from which an impedance changes discretely. It is a circuit diagram of a load variation unit using a plurality of variable phase shifters. It is a circuit diagram of an amplifying device having a load changing section using a plurality of variable phase shifters. (A) is a circuit diagram of a load fluctuation section in which impedance changes discretely, (b) is a diagram showing a circuit state when the switching element is OFF, and (c) is a diagram when the switching element is ON. It is a figure which shows the circuit state at the time. It is a circuit block diagram of the load fluctuation | variation part of Fig.33 (a). (A) is a circuit diagram of the load fluctuation | variation part from which an impedance changes discretely, (b) is a table | surface which shows the relationship between ON / OFF of a switching element, and an impedance. (A) is a circuit diagram of the load fluctuation part where impedance changes discretely, (b) is a figure which shows a circuit state when a switching element is ON, (c) is a switching element OFF It is a figure which shows the circuit state at the time. It is a circuit block diagram of the load fluctuation | variation part of Fig.36 (a). It is a circuit diagram of the load fluctuation | variation part which connected the some partial load fluctuation | variation part in series. (A) is explanatory drawing of the interference of the adjacent partial load fluctuation | variation part, (b) is explanatory drawing of the state which isolate | separated the adjacent partial load fluctuation | variation part for interference avoidance. It is a figure which shows arrangement | positioning of the partial load fluctuation | variation part in a circuit board. It is a figure which shows the example of the parallel connection of a partial load fluctuation | variation part. It is a circuit diagram of an amplifying device having a load changing section whose impedance changes discretely. It is a circuit of a load variation unit in which impedance changes discretely. It is explanatory drawing of the method of changing an impedance discretely. It is a circuit diagram which shows the 1st example of the load fluctuation | variation part from which an impedance changes with the shunt circuit provided in the transmission line. (A) is a Smith chart showing the variable range of impedance of the shunt circuit of FIG. 45, and (b) is a Smith chart showing the variable range of impedance of the load changing section of FIG. It is a circuit diagram which shows the 2nd example of the load fluctuation | variation part from which an impedance changes with the shunt circuit provided in the transmission line. It is a Smith chart which shows the variable range of the impedance of the load fluctuation | variation part shown in FIG. (A) is a circuit diagram which shows the 3rd example of the load fluctuation | variation part from which an impedance changes with the shunt circuit provided in the transmission line, (b) is a variable range of the impedance of the load fluctuation | variation part which concerns on a 3rd example. It is a Smith chart which shows. (A) is a circuit diagram which shows the 3rd example (fixed characteristic impedance) of the load fluctuation | variation part to which an impedance changes with the shunt circuit provided in the transmission line, (b) is a load fluctuation | variation part which concerns on a 3rd example. It is a Smith chart which shows the variable range of impedance. (A) is a circuit diagram which shows the 3rd example (line length is fixed) of the load change part from which an impedance changes with the shunt circuit provided in the transmission line, (b) is a load change part which concerns on a 3rd example. It is a Smith chart which shows the variable range of impedance. (A) is a circuit diagram which shows the 4th example of the load fluctuation | variation part from which an impedance changes with the shunt circuit provided in the transmission line, (b) is a variable range of the impedance of the load fluctuation | variation part which concerns on a 4th example. It is a Smith chart which shows. (A) is a circuit diagram which shows the 5th example of the load fluctuation | variation part from which an impedance changes with the shunt circuit provided in the transmission line, (b) is a variable range of the impedance of the load fluctuation | variation part which concerns on a 5th example. It is a Smith chart which shows. (A) is a circuit diagram showing a fifth example of the load fluctuation part impedance is changed by a shunt circuit provided to the transmission line (characteristic impedance = Z _{0), (b),} the load change according to the fifth example It is a Smith chart which shows the variable range of the impedance of a part. It is an example of a circuit which changes the impedance of the load change part of the 3rd example discretely. FIG. 56 is an equivalent circuit diagram of the circuit shown in FIG. 55. FIG. 56 is an equivalent circuit diagram of the circuit shown in FIG. 55. It is a figure which shows the impedance which the load fluctuation | variation part shown in FIG. 55 can take. It is an example of a circuit which changes the impedance of the load change part of the 3rd example discretely. It is an example of a circuit which changes the impedance of the load change part of the 3rd example discretely. It is a circuit diagram which shows the other example of a 1st shunt circuit. FIG. 62 is an explanatory diagram of a function of the 3λ / 8 line in FIG. 61. It is a circuit diagram which shows the other example of a 1st shunt circuit. It is a circuit diagram which shows the other example of a 1st shunt circuit. It is a circuit diagram which shows the other example of a 1st shunt circuit. It is a circuit diagram which shows the other example of a 1st shunt circuit.

Hereinafter, embodiments of the present invention and related techniques will be described with reference to the drawings.
[1. First Embodiment]
FIG. 1 shows an amplifying apparatus 101 according to the first embodiment. The amplifying apparatus 101 is mounted on a wireless communication apparatus such as a mobile terminal or a base station apparatus in a mobile communication system, and is used for amplifying a communication signal. The wireless communication apparatus is compliant with a scheme that handles wideband signals such as OFDM (including OFDMA) and W-CDMA. Signals in systems such as OFMD and W-CDMA rarely generate peak power. That is, the signals in these systems are signals accompanied by instantaneous power fluctuations. In the methods such as OFMD and W-CDMA, the ratio between the average power and the peak power is 3 dB or more.

An amplifying apparatus 101 shown in FIG. 1 has a circuit configuration conforming to a general LM system. That is, a constant envelope signal (a signal having a constant amplitude) having phase information but not amplitude information is given as an input (pre-amplification signal) to the amplifier 102 of the amplifying apparatus 101.
When the load (impedance) of the load changing unit 103 connected to the output side of the amplifier 102 fluctuates, the output signal of the amplifier 102 changes in amplitude. By changing the load impedance of the load changing unit 103 according to the amplitude fluctuation of the input signal, an output signal Pout having the same phase and amplitude as the phase and amplitude of the input signal is obtained.

  The amplifying apparatus 1 shown in FIG. 1 includes a processing unit 104 that performs signal processing on an I / Q signal that is an input signal. The processing unit 104 includes an amplitude calculation unit 104a that calculates the amplitude indicated by the I / Q signal, and a phase calculation unit 104b that calculates the phase indicated by the I / Q signal. That is, the processing unit 104 is a polar modulator that performs polar modulation on the I / Q signal.

  Furthermore, the processing unit 104 includes a load control unit 104c that generates a control signal for changing the load impedance of the load changing unit 103 based on the amplitude r calculated by the amplitude calculating unit 104a. The load control unit 104c increases the load impedance of the load variation unit 103 as the amplitude of the input signal (I / Q signal) decreases, and decreases the load impedance of the load variation unit 103 as the amplitude of the input signal increases. Generate a control signal.

  The control signal output from the load control unit 104 c is subjected to delay adjustment by the delay adjustment unit 105 and is then supplied to the load fluctuation unit 103. By including the delay adjusting unit 105, even if the output signal of the amplifier 102 is delayed or preceded by the control signal, the delay or the preceding can be eliminated and the timings of both signals can be matched. . Instead of the delay adjustment unit 105 or in addition to the delay adjustment unit 105, a delay adjustment unit may be provided on the input / output path (RF path) of the amplifier 102.

  The delay adjustment unit 105 can adjust the delay amount. For example, the time when the signal input to the amplifier 102 passes through the amplifier 102 changes depending on the temperature characteristics of the amplifier 102, and a time difference from the control signal is generated. However, the time difference can be corrected.

The phase signal output from the phase calculation unit 104b (a signal having only phase information in the input signal) is phase-modulated by the phase modulator 106 to generate a constant envelope signal (pre-amplification signal) having the phase information (FIG. 1 A1).
That is, the phase calculation unit 104b and the phase modulator 106 function as a conversion unit that converts an input signal (I / Q signal) including phase information and amplitude information into a constant envelope signal including phase information. To do. The constant envelope signal having phase information becomes an input signal to the amplifier 102.

  In the amplifier 102, a constant envelope signal having phase information is amplified. If the load impedance on the output side of the amplifier 102 is constant, the amplifier 102 simply outputs an amplified constant envelope signal, as indicated by B1 in FIG.

  However, since the load impedance of the load changing unit 103 changes according to the control signal output from the load control unit 104c, the output signal of the amplifier 102 becomes a signal whose amplitude fluctuates as shown by C1 in FIG. . Since the control signal is generated based on the amplitude information of the input signal, the amplitude fluctuation in the output signal of the amplifier 102 is the same as the amplitude fluctuation in the input signal. That is, the output signal Pout of the amplification device 101 is a signal having the same phase and amplitude as the phase and amplitude of the input signal. The output signal Pout is output from an antenna included in the wireless communication device.

Here, when the output voltage of the amplifier 102 is V and the load impedance on the output side of the amplifier 102 is Z, the output power Pout of the amplifier 102 is expressed by the following equation.
Pout = V ² / Z
It is clear from the above formula that the output of the amplifier 102 varies by varying the load impedance.

The amplifier 102 in the first embodiment is configured by switching amplifiers (SwitchingAmplifiers) such as class D, class E, and class F. The switching amplifier is an amplifier that performs a switching operation, and is also referred to as a digital amplifier.
Since the switching amplifier 102 basically operates in a saturated state at all times, the theoretical power efficiency is always 100% regardless of the magnitude of the output power.

  Since the switching amplifier is an amplifier in which the magnitude of the output power is constant, there has been no example of application to the LM system in which the output power (amplitude) of the amplifier needs to be varied. However, the present inventors dared to employ a switching amplifier as the amplifier 102 of the LM amplification device 101.

  The present inventors have described that the switching amplifier is an amplifier in which the magnitude of the output power is constant, but if the load impedance on the output side is changed in accordance with the amplitude fluctuation of the input signal, the output power of the switching amplifier ( It has been found that (amplitude) also varies in the same manner as the amplitude variation of the input signal.

  On the other hand, Non-Patent Document 1 uses a class B amplifier as an amplifier for the LM system. In the non-patent document 1, it is considered that the efficiency of the LM method is reduced at the time of low output because the class B amplifier is used.

That is, as shown in FIG. 2, in the LM method using the class B amplifier, the efficiency deteriorates when the output power Pout decreases (see Non-Patent Document 1). On the other hand, in the LM system using the switching amplifier 102, the efficiency deterioration can be suppressed even if the output power is reduced.
Theoretically, in the LM method using the switching amplifier 102, the efficiency is 100%. However, since the efficiency is reduced due to other factors, the theoretical value of the efficiency considering other factors is more than 100%. A slightly low value (for example, about 80%). In practice, in the case of low output, the efficiency is likely to decrease due to other factors.

For example, in Non-Patent Document 1, an unmodulated signal (sine wave) is used as an input signal, but when the input signal is a wideband signal (a signal accompanied by instantaneous power fluctuation), the power efficiency ( (E.g., 80%), the efficiency of the entire amplifying apparatus is further reduced accordingly.
On the other hand, in the LM system, an amplifier is operated under a constant voltage condition, and a highly efficient power source can be used.
Therefore, in Non-Patent Document 1, the LM method is considered to have a poorer performance than the SM method, but when the input signal is a wideband signal (a signal with instantaneous power fluctuation), the switching amplifier 102 is used. The efficiency of the LM amplification device is expected to be higher than that of the SM method.

[2. Second Embodiment]
FIG. 3 shows an amplifying apparatus 201 according to the second embodiment. In the following, the points that are not described in the second embodiment are the same as in the first embodiment. Further, in the drawings showing the following embodiments, the same or similar configurations between the embodiments have a common first digit number.

In the second embodiment, the phase calculation unit 104b of the processing unit 104 in the first embodiment is omitted, and an I / r calculation unit 204b-1 and a Q / r calculation unit 204b-2 are provided instead. .
The I / r calculation unit 204b-1 and the Q / r calculation unit 204b-2 divide each of the I signal and the Q signal by the magnitude of the amplitude r obtained by the amplitude calculation unit 204a. Therefore, the I / r signal and the Q / r signal are such that the amplitude information is deleted and only the phase information is indicated.

In the second embodiment, a quadrature modulator 206 is provided instead of the phase modulator 106 in the first embodiment.
The I / r signal and Q / r signal are quadrature modulated by the quadrature modulator 206 to generate a constant envelope signal (pre-amplification signal) having only phase information of the input signal (I / Q signal). (See A2 in FIG. 3).

The constant envelope signal (see A2 in FIG. 3) output from the quadrature modulator 206 is equivalent to the constant envelope signal (see A1 in FIG. 1) output from the phase modulator 106 of the first embodiment. is there.
Therefore, the amplifying apparatus 201 of the second embodiment can operate in the same manner as the amplifying apparatus 101 of the first embodiment.
In addition, the processing unit 204 of the second embodiment does not need to perform tan ⁻¹ calculations unlike the processing unit 104 of the first embodiment, and the calculation load is small.

[3. Third Embodiment]
FIG. 4 shows an amplifying apparatus 301 according to the third embodiment. In the following, the points that are not described in the third embodiment are the same as those in the first and second embodiments.
In the third embodiment, the I / r operation unit 204b-1 and the Q / r operation unit 204b-2 in the second embodiment are omitted.

  Therefore, each of the I / Q signals is input to the quadrature modulator 306 as it is. The quadrature modulator 306 outputs a modulation signal obtained by quadrature modulation of the I / Q signal, that is, a modulation signal having phase information and amplitude information.

In the LM method, amplitude information included in an input signal is reproduced by a load fluctuation unit at the subsequent stage of the amplifier. Therefore, it has been common knowledge so far that a constant envelope signal (see A1 in FIG. 1 and A2 in FIG. 3) having only phase information without amplitude information is given to the input of the LM amplifier.
On the other hand, in the third embodiment, unlike common sense in a general LM system, a modulated signal (a signal having amplitude information together with phase information) is input to the amplifier 302 (see A3 in FIG. 4).

However, since the amplifier 302 is a switching amplifier that operates in a saturated state, in the state where there is no load fluctuation by the load fluctuation unit 303, even if the quadrature modulation signal is input, the switching amplifier 302 basically performs amplification. The constant envelope signal having a constant amplitude is output. That is, the output signal of the switching amplifier 302 is a signal having phase information but no amplitude information (see B3 in FIG. 4) when there is no load fluctuation by the load fluctuation unit 303.
However, as in the first and second embodiments, the amplitude information included in the input signal is reproduced by the load changing unit 303, and the output signal Pout of the amplifier 302 has the same phase and amplitude as the phase and amplitude of the input signal. A signal having

  As described above, when the modulated signal whose amplitude varies passes through the switching amplifier 302, the amplitude information is basically lost. However, by inputting a modulation signal whose amplitude varies to the switching amplifier 302, the amplitude information originally included in the input signal is reproduced more accurately in the switching amplifier 302 in cooperation with the load variation unit 303. It becomes easy.

As a case where it is difficult to reproduce the amplitude information originally included in the input signal with only the load changing unit 303, there is a case where the load changing unit 303 cannot generate an infinite or sufficiently large load impedance.
In order to make the amplitude of the output signal of the switching amplifier 302 zero, for example, the value of the load impedance of the load changing unit 303 may be set to infinity.
However, when the load changing unit 303 cannot generate an infinite or sufficiently large load impedance, an output signal with zero amplitude cannot be obtained, and the amplitude information originally included in the input signal cannot be accurately reproduced.

  Even when the load impedance of the load changing unit 303 is infinite or sufficiently large, the amplitude is zero because of the internal impedance (output impedance) existing between the drain and source of the amplifier 302. Output signal may not be obtained. Since the internal impedance of the amplifier 302 exists in parallel with the load changing unit 303, even if the load impedance of the load changing unit 303 is increased, the combined impedance of the load changing unit 303 and the internal impedance is sufficient. May not grow. As a result, an output signal with zero amplitude cannot be obtained.

That is, as shown in FIG. 5A, even if the input signal is a signal that passes through the zero point or near the zero point on the IQ plane, the combined impedance of the load changing unit 303 and the internal impedance is not sufficiently large. The output signal of the amplifier 302 cannot take a value within the range C near the zero point as shown in FIG.
Therefore, the output signal of the amplifier 302 is a signal distorted from the input signal as shown in FIG.

  However, the present inventors have found that even if the switching amplifier 302 basically operates in a saturated state, if the input signal is zero or near zero, the output of the switching amplifier 302 is also zero. When the input of the switching amplifier 302 is zero, the output is zero rather than a constant envelope signal if the amplifier operates (theoretically) with 100% power efficiency.

  Therefore, in the amplifying apparatus 301 of the third embodiment, the amplitude fluctuation of the output signal is not caused only by the load fluctuation unit 303, but the fact that the amplitude of the input signal is zero or near zero is also utilized near zero. doing. As a result, as shown in FIG. 5C, the output signal of the amplifier 302 can take a value in the range C near the zero point, similarly to the input signal shown in FIG.

As described above, even when the load changing unit 303 alone cannot reproduce the amplitude information accurately, the amplitude information can be accurately reproduced by inputting the signal whose amplitude fluctuates to the switching amplifier 302.
That is, when the load impedance change by the load changing unit 303 is not considered, the switching amplifier 302 outputs a signal with zero amplitude when the input signal is zero or near zero, and the input signal can be larger than near zero. For example, the switching amplifier 302 operates in a saturated state and outputs a constant envelope signal.
When the input signal is zero or near zero, the switching amplifier 302 does not operate in a saturated state and the efficiency is reduced, but the probability that the input signal takes a value near zero or near zero is low. Therefore, as a whole, a decrease in efficiency is not a problem.

  Further, in the amplifying apparatus 301 according to the third embodiment, since it is not necessary to generate a zero signal by the load changing unit 303 alone, it is not necessary to generate a very large load impedance. For this reason, a value smaller than the load impedance required when the amplitude information is accurately reproduced by the load changing unit 303 alone may be the upper limit of the impedance value that can be changed in the load changing unit 303.

That is, even if the impedance of the load fluctuation unit 303 required when reproducing the amplitude information sufficiently accurately by the load fluctuation unit 303 alone is 1000Ω, the upper limit of the impedance fluctuation range of the load fluctuation unit 303 is For example, it can be set as 200Ω.
For this reason, the impedance fluctuation possible range of the load fluctuation part 303 can be narrowed, and it becomes easy to comprise the load fluctuation part 303 at low cost. Note that the upper limit value of the impedance variable range can be, for example, about the same as or higher than the internal impedance of the amplifier 302. The upper limit value of the impedance variable range is preferably about several times the internal impedance of the amplifier 302.

In an ideal switching amplifier, the current and voltage appear alternately with the ON / OFF switching operation, so there is no overlap between the current waveform and the voltage waveform, and the power efficiency is 100% as described above. .
However, in an actual switching amplifier, there is a slight overlap between the current waveform and the voltage waveform that are generated along with the ON / OFF switching operation, so that power is consumed inside the switching amplifier and the efficiency is lowered. The reduction in efficiency due to the overlap between the current waveform and the voltage waveform increases as the output power decreases.
Moreover, if an excessive input signal is input to the switching amplifier, the overlap between the current waveform and the voltage waveform becomes large, and the efficiency is lowered. Also, if an excessively small input signal is input to the switching amplifier, the switching operation cannot be performed, and the efficiency decreases rapidly.

From the above, in order to amplify a signal with amplitude fluctuation (power fluctuation) such as a wideband modulation signal while preventing the efficiency from being lowered by the switching amplifier 302, an excessive input signal or an excessive input signal is used. Avoiding this, it is desirable to set the load impedance value Z determined according to the amplitude of the input signal and the amplitude of the signal input to the switching amplifier 302 to appropriate values.
Therefore, it is desirable that the load control unit 304c generates the control signal so that the load impedance value Z determined according to the amplitude of the input signal is appropriate. In addition, it is preferable that the amplitude level of the signal input to the switching amplifier 302 is also adjusted appropriately.
In the amplifying apparatus 301 of the third embodiment, the point at which the power efficiency is maximized can be freely selected by the combination of the amplitude of the input signal and the load.

  Further, in the load control unit 304c of the third embodiment, as shown in FIG. 6, the load impedance value Z of the load changing unit 303 determined based on the amplitude (input power) r of the input signal is set to the upper limit set value. A control signal is generated so as to vary within a range between Zmax and the lower limit set value Zmin.

That is, the load control unit 304c does not change the value of Z in the entire range from the zero amplitude of the input signal to the maximum value (peak power value) rmax of the input signal amplitude, but the power of the input signal is the lower limit r. _{In a} range smaller than ₁ , the value of Z is not changed, and Z is constant at the upper limit set value Zmax. The power of the input signal is in a range larger than the upper limit value r ₂ does not vary the value of Z, Z is constant at the lower limit set value Zmin.

By limiting the variation range of the load Z in this way, the performance of the load variation function in the load variation unit 303 can be relaxed. In addition, even if the upper limit value of the fluctuation range of the load impedance Z is suppressed to the upper limit setting value Zmax, in the third embodiment, an excessive load is applied to the load fluctuation unit 303 by inputting the amplitude fluctuation signal to the switching amplifier 302. Since it is no longer necessary to generate Z, no problem occurs.
Further, as described above, when the input to the switching amplifier 302 becomes excessive, the efficiency is lowered, and thus the switching amplifier 302 should not be given an excessive input, and the lower limit value of the variation range of the load impedance Z is set to the lower limit. There are few problems even if it is suppressed to the set value Zmin. The lower limit set value Zmin is preferably an impedance that matches the output impedance of the amplifier 302.

In FIG. 6, Z varies linearly with respect to variations in the input signal when the input signal is between r _{1 and} r ₂ , but it is not necessary to vary linearly.
For example, as shown in FIG. 7, it may change stepwise with respect to fluctuations in the input signal. By varying the value of Z stepwise, it becomes easy to generate a control signal for controlling the value of Z from the amplitude information of the input signal. For example, when a lookup table is used to generate a control signal indicating the value of Z from an input signal, the table size can be reduced when the value of Z varies stepwise.

[4. Fourth Embodiment]
8 to 10 show an amplifying apparatus 401 according to the fourth embodiment. In the following, the points that are not described with respect to the fourth embodiment are the same as in the third embodiment.

The fourth embodiment shown in FIG. 8 includes a first distortion compensation unit (digital predistortion unit) 407 that performs processing for distortion compensation on the control signal output from the load control unit 404c.
Here, if power efficiency is to be maximized, the input signal and the output signal of the amplifier 402 are not linear, and distortion occurs in the output signal. However, ensuring linearity is important for the amplification device.

  FIG. 9A shows an example in which the combination of the input signal amplitude (input power) and the load value (control signal value) is optimized so that the power efficiency is maximized. In this case, the linearity is lost in the input / output characteristics of the amplifier 402 as shown in FIG. That is, from the viewpoint of increasing power efficiency in the load control unit 404c, if the relationship of the load (control signal value) to the input power (amplitude) is set as shown in FIG. 9A, the load control unit 404c. The load fluctuation unit 403 that operates in response to the control signal output from the circuit operates so as to cause nonlinear distortion in the output of the amplifier (switching amplifier) 402.

Therefore, in order to ensure linearity, the first distortion compensation unit 407 corrects the control signal (amplitude information). For example, when the control signal is not corrected, according to the relationship shown in FIG. 9A, when the input power Pin = 1.1 [W], the load control unit 404c determines the load of the load fluctuation unit 403. A control signal for setting the value to 9 [Ω] is generated. However, when the input power Pin = 1.1 [W], the same amplifier gain G = 10 as in the case of the input power Pin = 1 [W] cannot be obtained, which becomes nonlinear.
Therefore, when the input power Pin = 1.1 [W], in order to obtain the same amplifier gain G = 10 as in the case of the input power Pin = 1 [W] and ensure linearity, the first distortion The compensation unit 407 may correct the control signal so that the load value of the load changing unit 403 is 8 [Ω]. Thereby, output power Pout = 11 [W] is obtained, and linearity is ensured.

  However, if only the control signal (amplitude information) is corrected by the first distortion compensation unit 407, the “combination of the amplitude of the input signal and the load” optimized to maximize the power efficiency (FIG. 9 ( a)) will collapse. That is, if only the control signal (amplitude information) is corrected by the first distortion compensation unit 407, the load value of the load variation unit 403 becomes 8 [Ω] when Pin = 1.1 [W]. , Deviating from the combination of maximum power efficiency shown in FIG.

  Therefore, in order to maintain efficiency, as shown in FIG. 8, in addition to the first distortion compensation unit 407, a second distortion compensation unit (digital predistortion unit) 408 may be provided. The second distortion compensator 408 works in conjunction with the first distortion compensator 407 to correct the phase and / or amplitude of the I / Q signal, which is the input signal, so as to maximize the power efficiency. Distortion compensation is performed while maintaining a “combination of signal amplitude and load”.

  That is, the second distortion compensator 408, with the first distortion compensator 407 correcting the load (amplitude information), the power (amplitude) of the I / Q signal that is the input signal. By performing the correction, linearity is maintained while suppressing a decrease in power efficiency. For example, in the above example, when the first distortion compensation unit 407 corrects the control signal so that the load value of the load variation unit 403 is 8 [Ω], the second distortion compensation unit 408 What is necessary is just to correct | amend an input signal (I / Q signal) so that it may become the value of input power Pin = 1.2 in which maximum efficiency is acquired when is 8 [ohm].

  In addition, since the load fluctuation unit 403 may change the phase characteristic depending on the load value, the phase that changes corresponding to the correction of the load by the first distortion compensation unit 407 is changed to the second distortion compensation unit. It can also be corrected at 408.

However, if two distortion compensation units, the first distortion compensation unit 407 and the second distortion compensation unit 408, are provided, it is necessary to operate them in conjunction with each other, and the processing for distortion compensation becomes complicated.
Therefore, as shown in FIG. 10, by providing a distortion compensation unit (digital predistortion unit) 409 in front of the processing unit 404, two distortion compensations, a first distortion compensation unit 407 and a second distortion compensation unit 408, are provided. Even without providing a section, distortion compensation can be performed while maintaining the “combination of input signal amplitude and load” for maximizing power efficiency.

According to FIG. 10, the input signal after distortion compensation by the distortion compensation unit 409 is given to the load control unit 404c and also to the switching amplifier 402 side via the amplitude calculation unit 404a.
Therefore, the distortion compensator 409 maintains the optimized relationship from the viewpoint of power efficiency as shown in FIG. 9A while maintaining the amplitude of the input signal (and / or so that linearity can be obtained). If the phase is corrected, linearity can be obtained while maintaining power efficiency.

[5. Fifth Embodiment]
11 to 13 show an amplifying apparatus 501 according to the fifth embodiment. In the following, the points that are not described with respect to the fifth embodiment are the same as in the fourth embodiment.

As shown in FIG. 9A, the load control unit 404c in the fourth embodiment is set so as to generate a control signal in which the input / output characteristics of the amplifier are nonlinear but the power efficiency is maximized. .
In contrast, in the fifth embodiment, the distortion compensation units 407, 408, and 409 in the fourth embodiment are omitted. Further, in the load control unit 504c of the fifth embodiment, the relationship between the input power and the load (control signal value) is set so that a control signal in which the input / output characteristics of the amplifier are linear is generated. Since the load control unit 504c of the fifth embodiment also has the function of the first distortion compensation unit 407 of the fourth embodiment, although the efficiency is slightly reduced, the first distortion compensation unit 407 (DPD) ) Can be omitted.

In order to ensure the linearity of the amplifier, a DPD is necessary. However, if an independent function for correcting a signal in order to execute the DPD is incorporated in the amplifier, the cost increases.
On the other hand, as in the fifth embodiment, it is possible to suppress an increase in cost by providing the load control unit 504c also with the DPD function.

FIG. 12 shows the relationship between the input power (amplitude) and the load (control signal value) set in the load control unit 504c. The load control unit 504c includes a plurality of candidate values b _{1-1 that} can be arbitrarily selected for the same amplitude of the input signal (for example, input power Pin = 1) with respect to the magnitude of the load in the load changing unit 503. , B _1-2 , b _1-3 ,... _Are set. That is, when the input power Pin = 1, the load control unit 504c selects one of the plurality of candidate values b _1-1 , b _1-2 , b _1-3 ,. The value of the control signal for controlling the load changing unit 503 can be used. Similarly, when the input power Pin = 1.1, the load control unit 504c, a plurality of candidate values _{b 2-1, b 2-2, b 2-3} , any of ... One can be a value of a control signal for controlling the load changing unit 503.

  Thus, the load control unit 504c is set with a plurality of candidate values of the load magnitude in the load changing unit 503 for each value of the input power. The load control unit 504c can select one candidate value from the plurality of candidate values based on, for example, the output signal Pout and / or temperature of the amplification device.

  For example, when selecting a candidate value based on the output signal Pout of the amplifying device, even if nonlinear distortion is included in the output signal Pout, by selecting a candidate value that can eliminate the nonlinear distortion, linearity is improved. Can be secured.

  Further, when selecting a candidate value based on temperature, even if nonlinear distortion occurs due to a temperature change, the nonlinear distortion can be eliminated by selecting a candidate value corresponding to the temperature.

  The amplification device 501 shown in FIG. 13 is obtained by adding a power supply modulation unit 508 to the amplification device 501 shown in FIG.

  When distortion compensation is performed by DPD, not only the amplitude but also the phase can be corrected. However, even if the load control unit 504c that controls the load fluctuation unit 503 has a DPD function, only the amplitude can be corrected. Can not.

Therefore, when it is desired to correct the phase of the signal, the power source modulation unit 508 may perform power source modulation (drain modulation) of the amplifier 502. By finely adjusting the voltage or current value of the power source of the amplifier 502 by the power source modulation unit 508, the phase as well as the amplitude can be changed.
The power supply modulation unit 508 utilizes the fact that the phase can also be corrected by power supply modulation, and the amplitude and phase can be corrected by using the load control unit 504c and the power supply modulation unit 508 in combination.

As described above, according to the fifth embodiment, it is possible to correct a signal without incorporating an independent function for correcting the signal in order to execute DPD into the amplifying apparatus.
The amplifier 502 in the fifth embodiment is preferably a switching amplifier as in the previous embodiment, but the function of the load control unit 504c and the power supply modulation unit 508 in the fifth embodiment are not switching amplifiers. It can also be used in some cases.

[6. Load fluctuation section (load fluctuation device)]
[6.1 Load variation using signal synthesis]
FIG. 14 shows a load fluctuation unit (load fluctuation unit) 1001 that can be suitably used as the load fluctuation units 103, 203, 303, 403, and 503 in the amplification devices of the first to fifth embodiments.

The load changing unit 1001 illustrated in FIG. 14 includes two (plural) phase adjusters 1003a and 1003b. Each of the first phase adjuster 1003a and the second phase adjuster 1003b is supplied with a demultiplexed output signal obtained by demultiplexing the output signal of the amplifier 1002 (a signal passing through the load changing unit 1001) into a plurality of signals.
The demultiplexed output signals whose phases are adjusted by the phase adjusters 1003a and 1003b pass through impedance converters 1003c and 1003d made of λ / 4 lines (λ is a signal wavelength), and are combined by the combining unit 1003e. The combined output signal is output from the antenna 1010 of the wireless communication apparatus.

  The phase control unit 1011 controls the phase adjustment amount φ1 of the first phase adjuster 1003a and the phase adjustment amount φ2 of the second phase adjuster 1003b. That is, the first and second phase adjusters 1003a and 1003b adjust the phase difference between the plurality of demultiplexed output signals. Note that there is no need to provide a plurality of phase adjusters. For example, even one phase adjuster can adjust the phase difference between a plurality of demultiplexed output signals.

  According to the actual measurement results, when the two demultiplexed output signals were synthesized with the same phase (φ2−φ1 = 0 degree), the amplitude of the synthesized signal overlapped with the amplitude of the demultiplexed output signals. On the other hand, when the two demultiplexed output signals are synthesized with opposite phases (φ2−φ1 = 180 degrees), the demultiplexed output signals are canceled and the amplitude is reduced. When the value of φ2−φ1 (phase difference) was changed between 0 degree and 180 degrees, the amplitude varied according to the value of φ2−φ1 (phase difference). That is, it was confirmed that the circuit 1001 in FIG. 14 functions as a load changing unit.

Further, when the impedance of the load changing unit 1001 itself is measured, if the value of φ2−φ1 (phase difference) is changed between 0 degree and 180 degree, the load changing part 1001 is changed between 50Ω and 0Ω (short). It was confirmed that the resistance value changed.
Note that the maximum value of the resistance Z in the load changing unit 1001 can be set to a desired value by appropriately designing the impedance converters 1003c and 1003d composed of λ / 4 lines.

According to the load changing unit 1001 shown in FIG. 14, the load can be changed by controlling the phase adjusters 1003a and 1003b, so that it is easy to change the load at high speed.
Further, in the load changing unit 1001 of FIG. 14, by providing an isolator 1003f on the output side of the combining unit 1003e, even if the load viewed from the amplifier 1002 (the input impedance of the load changing unit 1001) changes, the load changing unit 1001 Fluctuations in output impedance can be suppressed. By suppressing fluctuations in the output impedance of the load fluctuation unit 1001, matching with the antenna 1010 can be ensured, and the operation is stabilized.

[6.2 First Example of Amplifying Device having Load Fluctuation Unit Using Signal Synthesis]
FIG. 15 shows a first example of an amplifying apparatus 601 having a load changing unit using signal synthesis. The amplifying device 601 in FIG. 15 is equivalent to the one in which the load changing unit 1001 in FIG. 14 is adopted as the load changing unit 303 in the third embodiment (FIG. 4). Note that the load changing unit 1001 in FIG. 14 can also be used in a general LM system amplifying apparatus that does not use a switching amplifier.

A demultiplexing output signal obtained by demultiplexing the output signal of the switching amplifier 602 into a plurality is supplied to the load changing unit 603 of the amplifying apparatus 601 in FIG. Each of the demultiplexed output signals whose phases are adjusted by the phase adjusters 603a and 603b of the load changing unit 603 passes through an impedance converter composed of a λ / 4 line (not shown in FIG. 15) and is synthesized by the synthesis unit 603e. .
The signal output from the combining unit 603e is given to the antenna side through the isolator 603f.

Further, in the amplifying apparatus 601 of FIG. 15, the first load control unit 604c-1 that functions as a phase control unit that controls the phase φ1 of the first phase adjuster 603a and the second phase adjuster 603b as the load control unit. And a second load control unit 604c-2 functioning as a phase control unit for controlling the phase φ2.
The load control units 604c-1 and 604c-2 generate control signals for controlling the phases φ1 and φ2 based on the amplitude information r of the input signal, and vary the load (resistance) Z in the load variation unit 603.
Note that delay adjustment units 605a and 605b are provided between the load control units 604c-1 and 604c-2 and the phase adjusters 603a and 603b.

[6.3 Second Example of Amplifying Device having Load Fluctuation Unit Using Signal Synthesis]
FIG. 16 shows a second example of an amplifying apparatus 601 having a load changing unit using signal synthesis. In addition, the point which abbreviate | omitted description in the 2nd example shown in FIG. 16 is the same as that of the 1st example shown in FIG.

In the amplification device 601 in FIG. 15, a demultiplexed output signal obtained by demultiplexing the output signal of one switching amplifier 602 is provided to the two phase adjusters 603a and 603b, whereas in the amplification device 601 in FIG. The modulated signal that is the output of the device 606 is demultiplexed into two, and the demultiplexed modulated signals are input to two (a plurality of) switching amplifiers 602a and 602b.
The output signals of the plurality of switching amplifiers 602a and 602b are supplied to the plurality of phase adjusters 603a and 603b. The signals whose phases are adjusted by the phase adjusters 603a and 603b are combined by the combining unit 603e. The signal output from the combining unit 603e is given to the antenna side through the isolator 603f.
In the amplifying apparatus 601 in FIG. 16, the amplified signal is not distributed, but the demultiplexed signal is amplified, so that the distribution loss is small and the efficiency is high.

[6.4 Third Example of Amplifying Device having Load Fluctuation Unit Using Signal Synthesis]
FIG. 17 shows a third example of an amplifying apparatus 701 having a load changing unit using signal synthesis. An amplification device 701 shown in FIG. 17 is obtained by adding a distortion compensation unit (digital predistortion unit) 709 similar to the distortion compensation unit 409 shown in FIG. 10 to the amplification device 601 of the second example shown in FIG. In addition, the point which abbreviate | omitted description in the 3rd example shown in FIG. 17 is the same as that of the 2nd example of FIG.

  In the amplifying apparatus 701 shown in FIG. 17, distortion generated in the output signal can be compensated for, as in the amplifying apparatus 401 shown in FIG.

[6.5 Fourth Example of Amplifier with Load Fluctuation Unit Using Signal Synthesis]
FIG. 18 shows a fourth example of an amplifying apparatus 701 having a load changing unit using signal synthesis. In addition, the point which abbreviate | omitted description in the 4th example shown in FIG. 18 is the same as that of the 3rd example of FIG.

In the third example shown in FIG. 17, the demultiplexed signals are amplified by the amplifiers 702a and 702b, and the phase of the output signals of the amplifiers 702a and 702b is adjusted by the phase adjusters 703a and 703b. Then, the signals adjusted in phase by the phase adjusters 703a and 703b are combined by the combining unit 703e.
On the other hand, in the fourth example shown in FIG. 18, the phase of the demultiplexed signal is adjusted by the phase adjusters 703a and 703b before amplification by the amplifiers 702a and 702b. Then, the signals whose phases are adjusted by the phase adjusters 703a and 703b are amplified by the amplifiers 702a and 702b.

  When a signal passes through the amplifiers 702a and 702b, the signal band may be widened depending on the distortion characteristics of the amplifiers 702a and 702b. In general, phase adjustment becomes more difficult as the signal becomes wider. However, in the fourth example shown in FIG. 18, phase adjustment is easy because the signals before the signals are widened by the amplifiers 702a and 702b may be adjusted.

[6.6 LINC for Amplifying Signals with Amplitude Information]
18 (and FIGS. 16 and 17) can be said to be an improvement of an amplifying apparatus of a LINC (L Inamplification using Nonlinear Components) system.
In the LINC method that performs linear amplification using a non-linear element, a modulated input signal (a signal including amplitude information) is decomposed into two constant amplitude signals (constant short signals) having different phases, and each signal has power. Amplified by a high-efficiency nonlinear amplifier, and a combination of these outputs is output.

More specifically, as shown in FIG. 19, in a general LINC-type amplifier 2001, the signal processing unit 2004 detects amplitude information included in an I / Q signal from an I / Q signal that is an input signal. Two phase information signals θ ₁ and θ ₂ that produce a phase difference corresponding to the output are output. The two phase information signals θ ₁ and θ ₂ are phase-modulated by the phase modulators 2006a and 2006b and become constant amplitude signals (constant short signals) having two different phases.

The two constant amplitude signals (constant short signal) having different phases are amplified by the two amplifiers 2002a and 2002b and synthesized by the synthesis unit 2003e.
Since each of the output signals of the two amplifiers 2002a and 2002b is a constant amplitude signal, the amplitude information is lost. However, since the phases of the output signals of the amplifiers 2002a and 2002b are different from each other, The amplitude information contained in the input signal is reproduced according to the phase relationship between the output signals.

  On the other hand, in the amplifying apparatus 701 shown in FIG. ) Is given.

Since the amplifiers 702a and 702b are switching amplifiers that operate in a saturated state, even if a quadrature modulation signal is input, the amplifiers 702a and 702b basically output an amplified constant envelope signal having a constant amplitude.
However, since the phase adjusters 703a and 703b provide a phase difference according to the amplitude of the input signal between the signals synthesized by the synthesizing unit 703e, the synthesized output signal of the synthesizing unit 703e The amplitude information contained in is reproduced.

However, when trying to obtain a composite signal (output signal) with zero amplitude, the phase difference between the two constant amplitude signals (constant short signal) must be strictly 180 °, and the phase difference is slightly less than 180 °. However, the amplitude does not become zero if it deviates. As a result, the amplitude information of the input signal cannot be accurately reproduced in the output signal.
As described above, in the conventional LINC method, it is difficult to generate an output signal having an amplitude near zero, which is an obstacle to practical use.

  On the other hand, in the amplification device 701 in FIG. 18 and the like, as in the LINC method, the amplitude information is reproduced in the combined output signal according to the phase difference between the signals amplified by the plurality of amplifiers 702a and 702b. A signal (modulation signal) having amplitude information is input to the amplifiers 702a and 702b.

Even if the switching amplifiers 702a and 702b basically operate in a saturated state, if the input signal is zero or near zero, the output of the switching amplifier 302 is also zero. Therefore, the amplification device 701 in FIG. 18 and the like does not cause amplitude fluctuation in the output signal only by the phase difference of the signal, but also utilizes that the amplitude of the input signal is zero or near zero in the vicinity of zero. ing.
Therefore, even when the amplitude information cannot be accurately reproduced by the signal phase difference alone, the amplitude information can be accurately reproduced by inputting the signal whose amplitude varies to the switching amplifiers 702a and 702b.
Note that in the amplifying apparatus 701 in FIG. 18 and the like, it is not necessary to generate a zero signal only by the phase difference, and therefore an error may be included in the phase difference.

[6.7 Load fluctuation section using variable phase shifter]
FIG. 20 shows another load fluctuation unit (load fluctuation unit) 3001 that can be suitably used as the load fluctuation units 103, 203, 303, 403, and 503 in the amplification devices of the first to fifth embodiments.

The load fluctuation unit 3001 shown in FIG. 20 uses a variable phase shifter. The circuit shown in FIG. 20 shows a circuit configuration in which a variable phase shifter having a branch line coupler is used as the load changing unit 3001. Note that the variable phase shifter is not limited to the one configured using the branch line coupler, and may be configured using another four-port circuit such as a rat-lace hybrid.
Further, the 4-port circuit functioning as a variable phase shifter does not need to be composed of a distributed constant circuit, and may be composed of a lumped constant circuit. For example, a lumped constant branch line coupler or a lumped constant rat race hybrid may be used as the variable phase shifter.

The branch line coupler is a 4-port circuit having a first port P1, a second port P2, a third port P3, and a fourth port P4. Four transmission lines 3011, 3012, 3013 and 3014 are provided between the ports P 1, P 2, P 3 and P 4. Each transmission line 3011, 3012, 3013, 3014 is a λ / 4 line.
The branch line coupler shown in FIG. 20 is a 3 dB branch line coupler, and the impedance of the transmission line 3011 between the first port P1 and the third port P3, and between the second port P2 and the fourth port P4. The impedance of the transmission line 3014 is Z ₀ / (√2), respectively (Z ₀ is the impedance of the system in the 3 dB branch line coupler). The impedance of the transmission line 3013 between the impedance of the transmission line 3012, and a third port P3 and fourth port P4 between the first port P1 and second port P2 is _{Z 0.}

The first port P1 is an input port to which a signal is input, and the second port is an output port to which a signal is output.
Variable impedances 3021 and 3022 are connected to the third port P3 and the fourth port P4, respectively. The variable impedances 3021 and 3022 are constituted by, for example, an inductor and a variable capacitance diode (varactor diode). The impedance of the variable impedances 3021 and 3022 can be changed by changing the voltage applied to the variable capacitance diode.

When the branch line coupler is used as a general variable phase shifter, the impedance values connected to the third port P3 and the fourth port P4 need to be the same value. Therefore, the same voltage is applied to each of the capacitive diodes constituting the variable impedances 3021 and 3022.
If the impedance values connected to the third port P3 and the fourth port P4 are the same, the signal input to the input port P1 is not reflected and is output from the output port P2 as it is. However, the signal output from the output port P2 has a phase changed with respect to the signal input to the input port P1.

The inventors of the present invention have an idea that the variable phase shifter can be used as a load variation unit (load variation unit) by independently adjusting the impedance values connected to the third port P3 and the fourth port P4. Got.
20, the values of the variable impedances 3021 and 3022 (values of the variable capacitance diodes) can be adjusted independently by the control unit 3031. That is, the load changing unit 3001 in FIG. 20 is provided so that the impedance difference between the impedance 3021 connected to the third port P3 and the impedance 3022 connected to the fourth port P4 can be adjusted.

The inventors experimentally show that when the impedance values connected to the third port P3 and the fourth port P4 are different, the signal input to the input port P1 is reflected and the input impedance changes. confirmed.
Also, if the impedance values connected to the third port P3 and the fourth port P4 are made different, the reflected power of the signal input to the input port P1 and the passing power passing from the input port P1 to the output port P2 are reduced. It was also confirmed that the balance changed.

FIG. 21 shows a voltage _VA applied to the variable impedance 3021 (variable capacitance diode) connected to the third port P3 and a voltage applied to the variable impedance 3022 (variable capacitance diode) connected to the fourth port P4. A change in the input impedance of the load changing unit 3001 when V _B is changed independently is shown.

21, S1 to S5 indicate impedances when the voltage difference (V _A −V _B ) is set as follows. When the voltage difference V _A −V _B (impedance difference) was adjusted, the impedance changed as indicated by S1 to S5 in FIG.
S1: (V _A −V _B ) = (0−12) = − 12 [V]
S2: (V _A −V _B ) = (4-8) = − 4 [V]
S3: (V _A -V _B ) = (4-4) = 0 [V]
S4: (V _A -V _B ) = (8-4) = 4 [V]
S5: (V _A −V _B ) = (12−0) = 12 [V]

FIG. 22A shows the relationship between the change in the voltage difference V _A −V _B and the reflected power of the signal input to the input port P1, and FIG. 22B shows the voltage difference V _A −V _B. The relationship between the change and the passing power passing from the input port P1 to the output port P2 is shown.
According to FIG. 22 (a), the A smaller absolute value of the voltage difference V _A -V _B, the reflected power is reduced, increasing the absolute value of the voltage difference V _A -V _B, that the reflected power increases Recognize.
On the other hand, according to FIG. 22B, when the absolute value of the voltage difference V _A -V _B is decreased, the passing power is increased, and when the absolute value of the voltage difference V _A -V _B is increased, the passing power is decreased. I understand that.

That is, when the voltage difference V _A −V _B (impedance difference) is changed, the balance between the reflected power and the passing power between the input port P1 and the output port P2 changes, and the input impedance of the load changing unit 3001 changes. I understand.

  However, in S <b> 1 to S <b> 5 of FIG. 21, when the load changing unit 3001 is viewed from the input port P <b> 1, it cannot be seen as a resistance. In order to make the load fluctuation unit 3001 look like a resistance when viewed from the input port P1, it is necessary to change the impedance as shown in S1 'to S5' of FIG. In order to change the impedance from S1 to S5 in FIG. 21 to 1 'to S5' in FIG. 21, the phase of the signal may be rotated in advance. In order to change the impedance in the clockwise direction on the Smith chart from S1 to S5 in FIG. 21 as shown in 1 ′ to S5 ′ in FIG. 21, the signal input to the input port P1 is changed as shown in FIG. The phase may be rotated in advance by the phase shifter 3040. Further, the influence by the phase shifter 3040 does not affect the impedance viewed from the port P2, the output impedance is constant, the input impedance can be changed, and the subsequent circuit or antenna is not affected.

  By appropriately rotating the phase by the phase shifter 3040, the impedance of the load changing unit 3001 can be changed as indicated by 1 'to S5' in FIG. Note that the phase shifter 3040 does not need to adjust the phase in order to make the load fluctuation unit 3001 appear as a resistor, and may adjust the phase so that a desired impedance characteristic can be obtained. Further, the phase shifter 3040 is configured as a variable phase shifter, and the impedance of the load changing unit 3001 can be changed by allowing the phase adjustment amount to be controlled from the outside.

It is preferable that the load fluctuation unit 3001 does not change the passing phase even when the load fluctuates. However, since the load changing unit 3001 originally uses what is configured as a variable phase shifter, the passing phase fluctuates due to load fluctuations.
Therefore, as shown in FIG. 23, a phase correction unit 3041 that corrects in advance the phase of the signal applied to the input port P1 in order to cancel the phase change that occurs when the input port P1 passes through the output port P3. It is preferable to provide it.

The phase correction unit 3041 receives a control signal instructing a phase correction amount corresponding to the load (voltage difference) from the control unit 3031 and performs phase adjustment on the signal. Thereby, even if a phase change occurs when passing from the input port P1 to the output port P3, the phase change can be canceled.
Note that the phase correction unit 3041 does not have to be provided before the input port P1 as shown in FIG. 23, and may be provided after the output port P2 as shown in FIG.
As shown in FIGS. 23 and 24, the load changing unit 3001 outputs the signal output from the output port (second port) via the isolator 3043, so that the load (input) of the load changing unit 3001 is output. The fluctuation of the output impedance of the load fluctuation section 3001 that occurs with the fluctuation of the impedance) can be suppressed.

[6.8 Amplifying device having a load fluctuation section using a variable phase shifter]
FIG. 25 shows an amplifying apparatus 801 having a load changing unit using a variable phase shifter. The amplifying device 801 shown in FIG. 25 is equivalent to a device that employs the load changing unit 3001 shown in FIG. 23 as the load changing unit 303 of the third embodiment (FIG. 4) and further includes an impedance converter 850 described later. Note that the load fluctuation unit 3001 in FIG. 23 can also be used for a general LM amplification device that does not use a switching amplifier.

  25 is connected to an amplifier 802 (switching amplifier) via an impedance converter 850. The amplifying device 801 in FIG. Similarly to the load variation unit 3001 shown in FIG. 23, the load variation unit 803 includes a phase shifter 840, a variable phase shifter including a four-port circuit, a variable impedance 821 connected to the third port of the variable phase shifter, A variable impedance 822 connected to the fourth port and an isolator 843 are provided.

In the amplifier device 801 of FIG. 25, as the load control unit, a first load control unit 804c-1 to control the impedance (voltage _{V A)} of the first variable impedance 821, the impedance of the second variable impedance 822 (voltage _V B) And a second load control unit 804c-2 for controlling. The first and second load control units 804c-1 and 804c-2 adjust the voltage difference added to the first and second variable impedances 821 and 822 based on the amplitude information r of the input signal, and the load variation unit The load (resistance) at 803 is varied.

  Note that delay adjustment units 805a and 805b that perform delay adjustment on the (first and second) control signals are provided between the load control units 804c-1 and 804c-2 and the variable impedances 821 and 822, respectively. When the response speed of the variable impedance (variable capacitance diode) 821 with respect to the control signal is slow, the delay adjustment is performed by the delay adjustment units 805a and 805b, thereby matching the signal timing with the output signal of the amplifier 802. Can do.

  25, the function corresponding to the phase correction unit 3041 in the load fluctuation unit 3001 in FIG. 23 is not clearly shown, but the function (phase correction function) corresponding to the phase correction unit 3041 is not limited to distortion compensation. This can be done in the section 809. In other words, since the phase varies according to the load in the load variation unit 803, the distortion compensation unit 809 performs phase correction on the I / Q signal in advance according to the input signal (amplitude), so that the load variation unit The phase change due to 803 can be canceled out. Moreover, since the distortion compensation unit (DPD) 809 can correct the digital IQ signal, the correction is easier than correcting the analog signal as shown in FIG.

The impedance converter (λ / 4 line) 850 provided between the amplifier 802 and the load changing unit 803 has a range in which the load changing range Z _{1 to} Z ₂ generated by the load changing unit 803 is necessary for the amplifier 802. Impedance conversion is performed so that

  In order to change the amplitude of the output signal of the amplifier 802 in accordance with the change of the load, the load of the load changing unit 803 is changed from a value Zamp that matches the output impedance of the amplifier 802 to a range Zamp to a higher impedance Zx. It is desirable to vary with Zx (Zx> Zamp).

However, the load fluctuation ranges Z _{1 to} Z _{2 of} the load fluctuation unit 803 are not necessarily in the desirable load fluctuation ranges Zamp to Zx viewed from the amplifier 802.
Therefore, the impedance converter 850 performs impedance conversion so that the load fluctuation range viewed from the amplifier 802 is within a desirable load fluctuation range viewed from the amplifier 802.

Here, in order to convert the load fluctuation ranges Z _{1 to} Z ₂ of the load fluctuation unit 803 into another range by impedance conversion, two types of conversion are conceivable.
One is a case where the maximum value Z ₂ of the load fluctuation ranges Z _{1 to} Z ₂ of the load fluctuation unit 803 is impedance-converted in correspondence with the impedance Zamp that matches the amplifier 802.
The other is a case where the minimum value Z ₁ of the load fluctuation ranges Z _{1 to} Z ₂ of the load fluctuation unit 803 is subjected to impedance conversion in correspondence with the impedance Zamp that matches the amplifier 802.

Among them, preferred load variation range as viewed from the amplifier 802 from the viewpoint of a Zamp～Zx, as the former, the _{Z 2,} preferably impedance conversion to match the impedance Zamp matching an amplifier 802 .

In other words, the maximum value _{Z 2} in correspondence with the impedance Zamp matching the amplifier 802, if the minimum value _{Z 1} in association with Zx to impedance conversion, when the impedance of the impedance converter 850 and Zline,
Zline ² = Zamp × Z ₂
Zline ² = Zx × Z ₁
It becomes.

Therefore,
Zx = Zline ² / Z ₁ = (Zamp × Z ₂ ) / Z ₁ = (Z ₂ / Z ₁ ) × Zamp
It becomes.
Since Z ₂ > Z ₁ , Zx has a larger impedance than Zamp. Therefore, a desirable state in the LM method is obtained in which the load fluctuates in the range Zamp to Zx (Zx> Zamp) of the impedance Zx higher than the value Zamp matching the output impedance of the amplifier 802.

On the other hand, when impedance conversion is performed in which the minimum value Z ₁ corresponds to the impedance Zamp matching the amplifier 802 and the maximum value Z ₂ corresponds to Zx,
Zline ² = Zamp × Z ₁
Zline ² = Zx × Z ₂
It becomes.

Therefore,
Zx = Zline ² / Z ₂ = (Zamp × Z ₁ ) / Z ₂ = (Z ₁ / Z ₂ ) × Zamp
It becomes.
Since Z ₂ > Z ₁ , Zx has an impedance smaller than Zamp. Therefore, the load fluctuates in a range of impedance lower than the value Zamp that matches the output impedance of the amplifier 802. If the impedance fluctuates in a range lower than Zamp, the efficiency decreases, which is not desirable for the LM system.

Therefore, it is preferable that the maximum value Z ₂ of the load fluctuation ranges Z _{1 to} Z ₂ of the load fluctuation unit 803 is impedance-converted in correspondence with the impedance Zamp that matches the amplifier 802.

[6.9 Low loss in load fluctuation section]
FIG. 27 shows variations of specific examples of the variable impedances 3021 and 3022 shown in FIGS. 20, 23, and 24 and the variable impedances 821 and 822 shown in FIG.
As described above, the variable impedances 3021, 3022, 821, and 822 connected to the third port P 3 or the fourth port P 4 of the branch line coupler can be configured by inductors and variable capacitance diodes (varactor diodes). FIGS. 27A and 27B show examples of variable impedances 3021, 3022, 821 and 822 constituted by an inductor 3025 and a variable capacitance diode (varactor diode) 3026, and FIG. 27C shows a variable capacitance diode. An example of a variable impedance that includes 3026 but does not include an inductor 3025 is shown. Note that the variable impedances 3021, 3022, 821, and 822 may include circuit elements other than the inductor and the variable capacitance diode.

  The variable capacitance diode 3026 is constituted by, for example, a varactor diode. The varactor diode 3026 has a cathode connected to the third port P3 or the fourth port P4 side, and an anode connected to the ground side.

The inductor 3025 may be an inductor (chip inductor) configured as a lumped constant element, or may be an inductor 3025a configured as a distributed constant line (microstrip line).
The inductor 3025 can be connected to the anode side of the variable capacitance diode 3026 as shown in FIG. That is, the anode of the variable capacitance diode 3026 can be connected to the ground via the inductor 3025.
The inductor 3025 can also be connected to the cathode side of the variable capacitance diode 3026 as shown in FIG. That is, the cathode of the variable capacitance diode 3036 can be connected to the third port P3 or the fourth port P4 via the inductor 3025.

  By providing the inductor 3025 as shown in FIGS. 27 (a) and 27 (b), the loss (loss) in the load changing portions 3001 and 803 is reduced as compared with the case where the inductor 3025 is not provided as shown in FIG. 27 (c). Can be reduced.

  FIG. 28 shows the loss rate of the load changing units 3001 and 803 including the variable impedances 3021, 3022, 821 and 822 provided with the inductor 3025 as shown in FIG. 27A, and as shown in FIG. The measurement result of the loss rate of the load fluctuation parts 3001 and 803 provided with the variable impedances 3021, 3022, 821 and 822 in which the inductor 3025 is omitted is shown. In the measurement, a lumped constant element was used as the inductor 3025.

Here, the loss rate is defined as follows. First, when the loss of the load change units 3001 and 803 is zero, the reflected power S ₁₁ (see FIG. 20) of the first port (input port) P1 of the load change units 3001 and 803 and the load change units 3001 and 803 The sum of the passing power S ₁₂ (see FIG. 20) from the first port (input port) P1 to the second port (output port) P2 is 1. The loss rate is expressed as follows using the reflected power and the passing power.
Loss rate = 1-(reflected power + passing power)

In order to obtain the measurement result of FIG. 28, the loss rate was measured by changing the voltage applied to each of the variable capacitance diodes 3026 connected to P3 and P4. The combinations of voltages applied to the variable capacitance diodes 3026 were set in 360 ways. In FIG. 28, the horizontal axis indicates the combination numbers 1 to 360.
As shown in FIG. 28, when the inductor 2025 is not provided in the variable impedances 3021, 3022, 821, 822, the loss rate is about 0.26-0.18 (26% -18%), while the variable impedance 3021 is , 3022, 821, and 822, the loss rate is about 0.22-0.14 (22% -14%), and it can be seen that the loss rate is improved.

  In addition, when the inductor 3025 is provided, the fluctuation width of the reflection coefficient of the variable capacitance diode 3026 is increased, and the fluctuation width of the impedance of the load changing units 3011 and 803 is also increased. That is, when the inductor 3025 is provided, an effect of increasing the variable range of the load changing units 3001 and 803 can be obtained.

When the inductor 3025 is configured by a lumped constant element (chip inductor), the inductor 3025 may be positioned at the position shown in FIG. 27A or the position shown in FIG. Therefore, the same loss reduction effect can be obtained.
On the other hand, when the inductor 3025 is constituted by a distributed constant line (microstrip line) 3025a, the position of the inductor 3025 is more lossy at the position shown in FIG. 27B than at the position shown in FIG. As a result of simulation, it has been found that the method is excellent from the viewpoint of reducing the above.

  Here, in order to reduce the loss of the load changing units 3001 and 803, it is only necessary to prevent the power from being wasted in the variable impedances 3021, 3022, 821, and 822. That is, if the reflected power from the variable impedances 3021, 3022, 821, 822 when viewed from the third port P 3 or the fourth port P 4 side is large, the loss of the load changing units 300 1, 803 can be reduced. In other words, the loss can be reduced by increasing the reflection coefficients of the variable impedances 3021, 3022, 821, and 822.

  The microstrip line 3025a functions as an impedance conversion circuit. Therefore, the loss can be reduced by providing the impedance conversion circuit 3025a so that the reflected power toward the third port P3 or the fourth port P4 is increased.

As shown in FIG. 29, the impedance (characteristic impedance) of the impedance conversion circuit 3025a is set to an impedance having a value different from the system impedance Z ₀ (for example, 50Ω) in the 3 dB branch line coupler. By setting the impedances to different values, the reflected power toward the third port P3 or the fourth port P4 can be increased.

When the impedance of the impedance conversion circuit (inductor) 3025a is larger than Z ₀ (= 50Ω), the impedance of the impedance conversion circuit 3025a is preferably 60Ω or more. In other words, the impedance of the impedance conversion circuit 3025a is preferably set to 120% or more of _{Z 0.} Furthermore, the impedance of the impedance conversion circuit 3025a is more preferable to be 70 ohm (140% or more _{Z 0).}

The characteristic impedance of the impedance conversion circuit 3025A, is made smaller than _{Z 0,} as compared with the case of greater than _{Z 0,} the heat loss is reduced in the variable impedance 3021,3022,821,822, losses, relatively Can be small.
When the impedance of the impedance conversion circuit (inductor) 3025a is made smaller than Z ₀ (= 50Ω), the impedance of the impedance conversion circuit 3025a is preferably 40Ω or less. In other words, the impedance of the impedance conversion circuit 3025a is preferably 80% or less of _{Z 0.} Furthermore, the impedance of the impedance conversion circuit 3025a is more preferable to be 30 [Omega (60% or less of _{Z 0).}

Thus, when the inductor 3025 at a distributed constant line, the inductor 3025 is located between the third port P3 or fourth port P4 and the variable capacitance diode 3026, and preferably less than _{Z 0.}

When an antenna is connected to the output of the amplifying device 801, it is amplified by the transmission line (amplifying device 801) of the amplifying device 801 so as to match the characteristic impedance Z ₀ (in many cases, 50Ω or 75Ω) of the antenna. The characteristic impedance Z ₀ (50Ω or 75Ω) of the signal transmission path) is set. Therefore, the system impedance Z ₀ in the 3 dB branch line coupler is also set to 50Ω or 75Ω.

[6.10 Load fluctuation section where impedance changes discretely]
FIG. 30 shows a configuration in which the impedance is discretely changed in the load changing section (load changing device) 3001 shown in FIG. 20 (FIGS. 23 and 24). 30 can also be used as the load fluctuation unit 803 of the amplifying apparatus 801 shown in FIG.

In the load changing unit 3001 shown in FIG. 30, the variable impedances 3021 and 3022 connected to the third port P3 and the fourth port P4 are configured so that the impedance changes discretely.
The first variable impedance 3021 connected to the third port P3 includes a plurality of impedances Z _A , Z _B ,... Z _X having different impedances. Further, the first variable impedance 3021 selects one of a plurality of impedances Z _A , Z _B ,... Z _X and connects the selected impedance to the third port P3 side (switching element). High-frequency switching element) 3028.
The second variable impedance 3022 connected to the fourth port P4 also includes a plurality of impedances Z _A , Z _B ,... Z _X having different impedances. Further, the second variable impedance 3022 selects one of a plurality of impedances Z _A , Z _B ,... Z _X and connects the selected impedance to the fourth port P4 side (switching element). High-frequency switching element) 3028.

The control element 3028 of the first variable impedance 3021 and the second variable impedance 3022 is controlled by the control unit 3031 and arbitrary impedances Z _A , Z _B ,... Z _X are selected, whereby the impedances of the variable impedances 3021 and 3022 are selected. The value of can be adjusted independently.
That is, the impedance difference between the variable impedances 3021 and 3022 also changes discretely. As a result, the balance between the reflected power and the passing power between the input port P1 and the output port P2 changes discretely, and the input of the load fluctuation unit 3001 Impedance changes discretely.
By making the impedance change discretely, it becomes easier to increase the speed than in the case where the impedance is changed continuously.

[6.11 Load variation section using multiple variable phase shifters]
FIG. 31 shows a load fluctuation unit (load fluctuation unit) 4001 using a plurality (two) of variable phase shifters.
A load changing unit 4001 shown in FIG. 31 corresponds to a unit using the variable phase shifter (load changing unit 3001) shown in FIG. 20 as the phase adjusters 1003a and 1003b of the load changing unit 1001 shown in FIG.

  That is, the load changing unit 4001 shown in FIG. 31 includes a first phase adjuster 4003a and a second phase adjuster 4003b. Each of the first phase adjuster 4003a and the second phase adjuster 4003b is supplied with a demultiplexed output signal obtained by demultiplexing the output signal of the amplifier 4002 (the signal passing through the load changing unit 4001) into a plurality of signals. Note that the phase adjusters 4003a and 4003b do not need to adjust only the phase, and for example, impedance conversion may be performed together.

  The demultiplexed output signals whose phases are adjusted by the phase adjusters 4003a and 4003b pass through the impedance converters 4003c and 4003d made of λ / 4 lines, and are combined by the combining unit 4003e. The combined output signal is output from the antenna 4010 of the wireless communication apparatus.

Each of the first phase adjuster 4003a and the second phase adjuster 4003b has the same configuration as the variable phase shifter (load fluctuation unit 3001) shown in FIG.
That is, each of the first phase adjuster 4003a and the second phase adjuster 4003b can be configured by a branch line coupler in the same manner as shown in FIG. In this case, each of the first phase adjuster 4003a and the second phase adjuster 4003b includes a four-port circuit (3 dB branch line coupler) having a first port P1, a second port P2, a third port P3, and a fourth port P4. And four transmission lines 4111, 4112, 4113, 4114 are provided between the ports P1, P2, P3, P4. Each transmission line 4111, 4112, 4113, 4114 is a λ / 4 line.

The impedance of the transmission line 4111 between the first port P1 and the third port P3 and the impedance of the transmission line 4114 between the second port P2 and the fourth port P4 are Z ₀ / (√2), respectively. (Z ₀ is the impedance of the system in the 3 dB branch line coupler). The impedance of the transmission line 4113 between the impedance of the transmission line 4112, and a third port P3 and fourth port P4 between the first port P1 and second port P2 is _{Z 0.}

The first port P1 is an input port to which a demultiplexed output signal is input, and the second port is an output port to which a signal is output.
Variable impedances 4121 and 4122 are connected to the third port P3 and the fourth port P4 in the first phase adjuster 4003a and the second phase adjuster 4003b, respectively. The variable impedances 4121 and 4222 are constituted by, for example, an inductor and a variable capacitance diode (varactor diode). As the variable impedances 4121 and 4222, any of the three configurations shown in FIGS. 27A, 27B, and 27C may be adopted. As the variable impedances 4121 and 4222, a variable impedance (variable impedance in which impedance changes discretely) 3028 shown in FIG. 30 may be adopted.

  The load (impedance) of the load changing unit 4001 can be changed by adjusting the phase difference between the plurality of demultiplexed output signals by the first phase adjuster 4003a and the second phase adjuster 4003b which are variable phase adjusters. it can.

表１において、Γ_１は、第１位相調整器４００３ａの可変インピーダンス４１２１の反射係数であり、Γ_２は第１位相調整器４００３ａの可変インピーダンス４１２２の反射係数であり、Γ_３は第２位相調整器４００３ａの可変インピーダンス４１２１の反射係数であり、Γ_４は第２位相調整器４００３ａの可変インピーダンス４１２２の反射係数である。Ｚ_１，Ｚ_２，Ｚ_３，Ｚ_４は、上記のＺ_ｉの式に従ってΓ１，Γ２，Γ３，Γ４から算出される可変インピーダンス４１２１，４１２２のインピーダンスである。
なお、表１では、反射係数の絶対値の大きさと位相角とを変化させて、所望の入力インピーダンスを設定しているが、絶対値の大きさを変えず、位相角だけを変化させることでも、同様に入力インピーダンスを設定することが可能である。 In the load changing unit 4001, the values of the four variable impedances 4121 and 4122 can be adjusted independently by the control unit 4031.
When the values of the variable impedances 4121 and 4122 of the first phase adjuster 4003a and the second phase adjuster 4003b are appropriately adjusted according to the control signal (first control signal to fourth control signal) of the control unit 4031, load fluctuation While changing the input impedance of the unit 4001 (impedance viewed from the amplifier 4002 side), the output impedance of the load variation unit 4001 (impedance viewed from the antenna 4010 side) can be made substantially constant. By adjusting the values of the variable impedances 4121 and 4122, the balance between the reflected power and the passing power of the first phase adjuster 4003a and the second phase adjuster 4003b can be adjusted, and the output impedance of the load fluctuation unit 4001 can be adjusted. This is because the input impedance can be changed without being changed.
Therefore, in the load changing unit 4001 shown in FIG. 31, it is not necessary to provide an isolator in order to suppress fluctuations in output impedance (however, an isolator may be provided).
For example, by setting the voltage reflection coefficient Γ _i (i = 1 to 4) values of the variable impedances 4121 and 4122 of the first phase adjuster 4003a and the second phase adjuster 4003b as follows, the load fluctuation unit While making the output impedance (50Ω) of 4001 constant, the input impedance of the load changing unit 4001 can be changed (50Ω, 82Ω, 120Ω).

In Table 1, Γ ₁ is the reflection coefficient of the variable impedance 4121 of the first phase adjuster 4003a, Γ ₂ is the reflection coefficient of the variable impedance 4122 of the first phase adjuster 4003a, and Γ ₃ is the second phase adjustment. ₄ is the reflection coefficient of the variable impedance 4122 of the second phase adjuster 4003a. _{Z 1, Z 2, Z 3} , Z 4 are, .GAMMA.1 according to the formula above _{Z i, Γ2, Γ3,} the impedance of the variable impedance 4121,4122 calculated from [gamma] 4.
In Table 1, the desired input impedance is set by changing the magnitude and phase angle of the reflection coefficient, but it is also possible to change only the phase angle without changing the magnitude of the absolute value. Similarly, it is possible to set the input impedance.

  31 includes a phase shifter 4140 and a phase correction unit 4141. The phase shifter 4140 and the phase correction unit 4141 are the same as the phase shifter 3040 and the phase correction unit 3041 shown in FIGS.

In other words, the phase shifter 4140 changes the impedance of the load changing unit 4001 from S1 to S5 in FIG. 21 to S1 ′ to S5 ′ in FIG. 21 by appropriately rotating the phase, thereby changing the load changing unit 4001. In order to make a resistor appear or to obtain a desired impedance characteristic.
The phase correction unit 4141 is for correcting a change in phase that occurs when a signal passes through the load fluctuation unit 4001.

  In FIG. 31, an impedance converter 4150 is connected to the load changing unit 4001. The impedance converter 4150 is configured by a λ / 4 transmission line, and has the same function as the impedance converter 850 in the amplification device 801 shown in FIG. That is, by providing the impedance converter 4150, the impedance of the load changing unit 4001 can be changed to be high.

[6.12 Amplifying apparatus having a load fluctuation section using a variable phase shifter]
FIG. 32 shows an amplifying apparatus 901 having a load changing unit using a variable phase shifter. 32 is equivalent to the amplifying apparatus 801 shown in FIG. 25, in which the load changing unit 803 is replaced with the load changing unit 4001 shown in FIG. That is, the amplifying apparatus 901 in FIG. 32 includes a load fluctuation unit 903 similar to the load fluctuation unit 4001 in FIG.
In the amplification device 901 in FIG. 32, the amplifier 902 is a switching amplifier, but may not be a switching amplifier.

  32 includes a control unit 904c that generates first to fourth control signals as a load control unit. The control unit 904c controls the values of the variable impedances 4121 and 4122 of the first phase adjuster 4003a and the second phase adjuster 4003b based on the amplitude information r of the input signal, and loads (resistances) in the load variation unit 903. Fluctuate. The first to fourth control signals are signals for controlling the four variable impedances 4121 and 4122.

  Note that delay adjustment units 905a, 905b, 905c, and 905d that perform delay adjustment for the (first to fourth) control signals are provided between the control unit 904c and the variable impedances 4121 and 4122. By adjusting the delay by the delay adjustment units 905a, 905b, 905c, and 905d, the signal timing can be matched with the output signal of the amplifier 902.

32, the function corresponding to the phase correction unit 4141 (phase correction function) can be performed by the distortion compensation unit 909.
In addition, an impedance converter (λ / 4 line) 950 provided between the amplifier 902 and the load fluctuation unit 903 requires load fluctuation ranges Z _{1 to} Z ₂ generated by the load fluctuation unit 903 as the amplifier 902. Impedance conversion is performed so as to be within a range.

In the amplifying apparatus 901 of FIG. 32, a demultiplexed output signal obtained by demultiplexing one switching amplifier 902 output signal is provided to the two phase adjusters 4003a and 4003b.
However, as in the amplifying apparatus 601 in FIG. 16, the modulation signal that is the output of the quadrature modulator 906 may be split into two, and the split modulation signal may be input to two (plural) amplifiers. .
Further, as in the amplifying apparatus 701 of FIG. 18, the phase of the divided signal may be adjusted by the phase adjusters 4003a and 4003b before amplification by a plurality (two) of amplifiers.

[6.13 Load variation section in which impedance changes discretely]
33 and 34 show a load changing unit 5001 in which impedance changes discretely. The load fluctuation unit 5001 can be suitably used as the load fluctuation units 103, 203, 303, 403, and 503 in the amplification devices of the first to fifth embodiments.
The load changing unit 5001 includes a plurality (two) of impedance conversion units 5011 and 5012 connected in parallel.
The first impedance converter (first transmission line) 5011 and the second impedance converter (second transmission line) 5012 each have a λ / 4 transmission line (having a line length of λ / 4) configured by microstrip lines. Transmission line).

Of the two impedance conversion units 5011 and 5012, one impedance conversion unit (second impedance conversion unit) 5012 includes a high-frequency switching element (control element) 5021.
In FIG. 34, since the line widths of the two impedance converters 5011 and 5012 are different, both line impedances are different, but may be the same.

  The switching element 5021 can be configured by, for example, a PIN diode 5021a, and can be switched to a conductive state or a non-conductive state. As shown in FIG. 34, by connecting an inductor (additional element) 5022 in parallel to the switching element 5021, a more complete conduction state or non-conduction state can be obtained when the switching element 5021 and the inductor 5022 constitute a resonance circuit. Can do. Note that the additional element 5022 is not limited to an inductor, and may be any suitable element for obtaining a resonance circuit according to the impedance characteristics of the switching element 5021.

  The switching element 5021 is connected to the center position of the second impedance converter (second transmission line) 5012. In other words, the switching element 5021 is connected to a position where the line length from the end of the λ / 4 transmission line 5012 is λ / 8. The position where the switching element 5021 is connected is a position where the λ / 4 transmission line 5012 is divided into two λ / 8 transmission lines 5012a and 5012b.

As shown in FIG. 33B, when the switching element 5021 is in a non-conduction state (OFF), the presence of the switching element 5021 can be ignored. Therefore, the entire load changing unit 5001 is a parallel circuit of two transmission lines 5011 and 5012. In this case, the impedance of the load change unit 5001 is a composite impedance of the line impedance _{Z 2} of the line impedance _{Z 1} and the second impedance converter 5012 of the first impedance converter 5011 _(Z 1 // _{Z 2).}

  On the other hand, as shown in FIG. 33 (c), when the switching element 5021 is in a conductive state (ON), the second transmission line 5012 becomes two stubs (short stubs) 5012a and 5012b. Therefore, the entire load changing unit 5001 is a π-type circuit in which two λ / 8 short stubs 5012a and 5012b are connected to both sides of the λ / 4 first transmission line 5011. In this case, the impedance of the load changing unit 5001 is a combined impedance in the π-type circuit.

Thus, by switching the element state (conducting state / non-conducting state) of the switching element 5021, the load changing unit 5001 can be switched to a parallel circuit or a π-type circuit of the transmission lines 5011 and 5012. Since the impedance differs between the parallel circuit of the transmission lines 5011 and 5012 and the π-type circuit, the impedance can be changed by switching the conduction state / non-conduction state of the switching element 5021.
That is, the impedance of the load changing unit 5001 can take two impedance values, that is, the first impedance of the parallel circuit of the transmission lines 5011 and 5012 and the second impedance of the π-type circuit. As described above, the load changing unit 5001 discretely changes the impedance into two types of values.
When it is not necessary to discretely change the impedance of the load changing unit 5001, the control element 5021 is not limited to a switching element but may be a variable impedance element.

  In FIG. 33, an auxiliary impedance converter 5002 is connected to the load changing unit 5001. The auxiliary impedance conversion unit 5002 is configured by a λ / 4 transmission line, and has the same function as the impedance converter 850 in the amplification device 801 shown in FIG. That is, by providing the auxiliary impedance conversion unit 5002, the impedance of the load variation unit 5001 can be varied to a high level.

  The number of impedance converters (transmission lines) 5011 and 5012 constituting the load changing unit 5001 is not limited to two, and may be three as shown in FIG. FIG. 35A shows a load variation unit 5001 having three impedance conversion units 5011, 5012, and 5013. The number of impedance conversion units constituting the load changing unit 5001 may be three or more.

In the load changing unit 5001 in FIG. 35A, the first to third switching elements (control elements) 5021a, 5021b, and 5021c are connected to all the impedance conversion units 5011, 5012, and 5013 constituting the load changing unit 5001, respectively. Has been. In this case, as shown in FIG. 35B, the impedance of the entire load variation unit 5001 is changed by appropriately switching ON / OFF (conduction / non-conduction) of each of the first to third switching elements 5021a, 5021b, 5021c. , Z _{A to} Z _G can be changed discretely.

  As shown in FIGS. 36 and 37, the switching element (control element) 5021 may be connected in series so as to be interposed in the middle position of the second impedance converter 5012. That is, the switching element 5021 may be connected in series between the two separated λ / 8 transmission lines 5012a and 5012b.

As shown in FIG. 36B, when the switching element 5021 is in the conductive state (ON), the two λ / 8 transmission lines 5012a and 5012b are connected in series to form one λ / 4 transmission line 5012. . Therefore, the entire load changing unit 5001 is a parallel circuit of two transmission lines 5011 and 5012. In this case, the impedance of the load change unit 5001 is a composite impedance of the line impedance _{Z 2} of the line impedance _{Z 1} and the second impedance converter 5012 of the first impedance converter 5011 _(Z 1 // _{Z 2).}

On the other hand, as shown in FIG. 36C, when the switching element 5021 is in a non-conduction state (OFF), the second transmission line 5012 becomes two stubs (open stubs) 5012a and 5012b. Therefore, the entire load changing unit 5001 is a π-type circuit in which two λ / 8 open stubs 5012a and 5012b are connected to both sides of the λ / 4 first transmission line 5011. In this case, the impedance of the load changing unit 5001 is a combined impedance in the π-type circuit.
As a result, also in the load changing unit 5001 shown in FIGS. 36 and 37, the impedance can discretely change into two types of values.

  The load change unit 5001 shown in FIG. 38 is configured by combining the load change unit 5001 shown in FIGS. 33 to 37 as one partial load change unit and a plurality (three) of partial load change units 5001a, 5001b, and 5001c. It is a thing.

In FIG. 38, a plurality of partial load fluctuation units 5001a, 5001b, 5001c are cascaded in series.
A control signal (first to third control signals) is supplied from the control unit 5031 to each of the plurality (three) of partial load changing units 5001a, 5001b, and 5001c. Each of the switching elements 5021 of the partial load changing units 5001a, 5001b, and 5001c is ON / OFF controlled by a control signal.

Since the load changing unit 5001 includes a plurality of partial load changing units 5001a, 5001b, and 5001c, the types of impedance values of the load changing unit 5001 can be increased.
In one partial load fluctuation unit, assuming that the type of impedance value that varies discretely is A and the number of partial load fluctuation units constituting the load fluctuation unit 5001 is N, the impedance value of the entire load fluctuation unit 5001 is of the kind, the ^{a N.}

In particular, when the partial load variation unit is configured as shown in FIGS. 33 (34) and 36 (FIG. 37), the number of switching elements 5021 included in one partial load variation unit is one. in the switching element 5021, it is possible to realize a ^{a N} type impedance. That is, when a load variation unit is configured by three partial load variation units, 2 ³ = 8 types of impedances can be expressed by ^three switching elements.
Thus, various impedances can be realized by a relatively small number of switching elements 5021.

  When connecting a plurality of partial load change parts 5001a, 5001b, 5001c in series, as shown in FIG. 39 (a), when adjacent partial load change parts 5001a, 5001b, 5001c are arranged close to each other, they are adjacent. Interference occurs between the partial load fluctuation units 5001a, 5001b, and 5001c.

  On the other hand, as shown in FIG. 39 (b), in order to avoid interference, when the transmission lines are interposed between the adjacent partial load fluctuation parts 5001a, 5001b, 5001c and the adjacent partial load fluctuation parts are separated, The impedance of the entire load changing unit 5001 is affected by the transmission line. In order to avoid the influence of the transmission line, it is necessary to use the λ transmission line having a line length of λ so that the adjacent partial load changing parts 5001a, 5001b, and 5001c are arranged close to each other to have the same characteristics. . When it is necessary to provide the λ transmission line, the load changing unit 5001 is enlarged.

  Therefore, as shown in FIG. 40, the plurality of partial load changing portions 5001a, 5001b, and 5001c are alternately positioned on the front surface 5051 and the back surface 5052 of the circuit board (double-sided board) 5050, thereby avoiding interference, Increase in size can be prevented.

  For example, in the load variation unit 5001 shown in FIG. 40, the first partial load variation unit 5001a is formed on the surface 5051 of the circuit board 5050 on which circuit patterns are formed on both the front and back surfaces. A second partial load variation unit 5001b adjacent to the first partial load variation unit 5001a is formed on the back surface 5052 and is connected to the first partial load variation unit 5001a formed on the front surface 5051 through a through hole 5053. . A third partial load variation unit 5001c adjacent to the second partial load variation unit 5001b is formed on the front surface 5051 and connected to the second partial load variation unit 5001b formed on the back surface 5052 through the through hole 5054. .

  Note that, in a load variation unit having a plurality of partial load variation units, the plurality of partial load variation units need not be connected in series in a line. For example, as shown in FIG. 41A, the load changing unit 5001 includes a plurality of (two) partial load changing units 5001a and 5001b connected in series and another plurality (two) partial load changing units. 5001c and 5001d connected in series may be connected in parallel.

Further, as shown in FIG. 41 (b), the load changing unit 5001 is further different from the partial load changing units 5001a, 5001b, 5001c, and 5001d connected as shown in FIG. 41 (a). The variable part 5001e may be connected in series. In this way, it is possible to connect a plurality of partial load fluctuation units by various connection methods.
As shown in FIG. 41, a loss can be suppressed by connecting a plurality of partial load changing units in parallel as much as possible, as compared to a case where all the partial load changing units are connected in series.

[6.14 Amplifying apparatus having a load changing section whose impedance changes discretely]
FIG. 42 shows an amplifying device 951 having a load changing unit whose impedance changes discretely. The amplification device 951 in FIG. 42 is substantially equivalent to the amplification device shown in FIG. 25, in which the load fluctuation unit 803 is replaced with the load fluctuation unit 5001 in FIG. That is, the amplifying apparatus 951 in FIG. 42 includes a load variation unit 953 similar to the load variation unit 5001 in FIG. The load of the load changing unit 953 changes discretely.
In the amplification device 951 in FIG. 42, the amplifier 952 is a switching amplifier, but may not be a switching amplifier.

  In the amplifying device 951 in FIG. 42, first to first control units for controlling (switching ON / OFF) the switching elements 5021 of the partial load changing units 5001a, 5001b, and 5001c constituting the load changing unit 953 as load control units. A load control unit 954c that generates 3 control signals (ON / OFF signals) is provided. The load control unit 954c controls each switching element 5021 based on the amplitude information r of the input signal, and varies the load in the load variation unit 903.

  Note that delay adjustment units 955a, 955b, and 955c that perform delay adjustment for each of the (first to third) control signals are provided between the load control unit 954c and the partial load fluctuation units 5001a, 5001b, and 5001c. . By adjusting the delay by the delay adjusting units 955a, 955b, and 955c, the signal timing can be matched with the output signal of the amplifier 902.

Note that the amplification device 951 in FIG. 42 can also have a function corresponding to the phase correction unit. That is, the change in the passing phase that occurs in the load fluctuation unit 5001 can be corrected by the phase correction unit. However, in FIG. 42, the function of the phase correction unit can be performed by the distortion compensation unit 959.
Further, an impedance converter (λ / 4 line) 960 is provided between the amplifier 952 and the load changing unit 953. The impedance converter 960 performs impedance conversion so that the load fluctuation ranges Z _{1 to} Z ₂ generated by the load fluctuation unit 953 are within a range necessary for the amplifier 952.

  In addition, the load changing unit 953 is provided with an isolator 5003. By providing the isolator 5003 at the final stage of the load fluctuation unit 953, even if the load (input impedance of the load fluctuation unit 953) seen from the amplifier 952 fluctuates, fluctuations in the output impedance of the load fluctuation unit 953 can be suppressed. . By suppressing fluctuations in the output impedance of the load fluctuation unit 953, matching with the antenna connected to the output side of the load fluctuation part 953 can be ensured, and the operation is stabilized.

[6.15 Another Example of Load Fluctuation Unit with Impedance Discretely Changing]
FIG. 43 shows a load changing unit 6001 in which impedance changes discretely. The load changing unit 6001 includes a plurality of load units 6011, 6012, 6014, 6014, and 6015 having different impedances. The load units 6011 to 6015 can be configured by, for example, an impedance conversion unit (transmission line; microstrip line).

The load changing unit 6001 includes switch units 6021 and 6022 for alternatively selecting one of the plurality of load units 6011 to 6015. Each of the switch units 6021 and 6022 includes a plurality of switching elements (high frequency switching elements).
The load (impedance) of the load changing unit 6001 is the impedance of the load unit selected from among the plurality of load units 6011 to 6015. That is, the load changing unit 6001 changes impedance discretely.

  43 is easy to design because the number of switching elements tends to be larger than the number of impedance values that the load fluctuation unit 6001 can take, but the configuration is simple.

[6.16 Method of discretely changing impedance]
In the load modulation type amplifying apparatus, the value of the load (impedance) of the load varying unit varies according to the temporal variation of the input signal (modulated signal) of the amplifying apparatus. That is, the input signal (modulation signal) of the amplification device is a reference signal (a signal that varies with time) that serves as a reference for varying the load.

Here, according to the Nyquist theorem, if the discretization is performed at a frequency that is at least twice the modulation bandwidth of the signal, all the information in the signal band can be stored.
Therefore, when trying to discretely change the impedance of the load fluctuation section, the load value is discretely set at a rate more than twice the bandwidth (transmission bandwidth) of the reference signal that becomes the reference of the load fluctuation. Change it. As a result, even if the load is changed discretely, the same result as that obtained when the load is continuously changed can be obtained.

  In addition, by changing the load (impedance) discretely, it is easy to speed up the change of the load as compared with the case of continuously changing the load.

FIG. 44 is a diagram for explaining a number of the already described amplifying devices from the viewpoint of the load changing speed in the load changing unit. 44 may be a load fluctuation unit shown in the drawings after FIG.
44, the load modulation type amplifying apparatus 11 includes an amplifier 12 and a load fluctuation unit (load fluctuation unit) 13 connected to the output side of the amplifier 12.

  The load changing unit 13 includes an input unit 13a to which a signal (pass signal) is input, a load changing unit main body (load variator main body) 13b capable of changing a load value for the signal input to the input unit 13a, a load An output unit 13c that outputs a signal output from the fluctuation unit main body 13b, and a control signal input unit 13d that receives a control signal for changing the load value of the load fluctuation unit main body 13b are provided.

When the load changing unit 13 is configured by a unitized (chiped) circuit independently of the other circuit elements of the amplifier, each of the input unit 13a, the output unit 13c, and the control signal input unit 13d For example, it corresponds to a terminal for signal input / output in a unitized circuit.
When the load changing unit 13 is not unitized, the input unit 13a, the output unit 13c, and the control signal input unit 13d are connected to the load changing unit 13 from other circuit elements in the amplifier. The part corresponds.

  The input unit 13a is connected to the output side of the amplifier 12, the output unit 13c is connected to the antenna side, and the control signal input unit 13d is connected to the load control unit 14c.

  The load control unit 14c is for controlling a change in the load of the load changing unit main body 13b. Based on the amplitude information r of the input signal, the load control unit 14c generates a control signal (such as an ON / OFF signal for the switching element) that changes the load of the load changing unit body 13b. The control signal generated by the load control unit 14c is obtained by discretely dividing the load of the load fluctuation unit main body 13b at a rate not less than twice (2 × f [Hz]) of f when the bandwidth of the input signal is f [Hz]. It is a digital signal that is changed in an automatic manner. That is, the signal rate of the control signal is 2 × f [Hz] or more.

  The operation rate of the load variation unit 13 (load variation unit body 13b) is also the same as the signal rate of the control signal, and is a rate equal to or greater than twice (2 × f [Hz]) f. Therefore, in the load changing unit 13, the load changes discretely at a rate that is twice or more the bandwidth of the input signal (reference signal).

[6.17 Load fluctuation section where impedance changes by shunt circuit]
Hereinafter, a plurality of examples of the load changing unit 5001 whose impedance is changed by a shunt circuit provided in the transmission line will be described. A plurality of examples of the load changing unit 5001 described below can be suitably used as the load changing units 103, 203, 303, 403, and 503 in the amplifying devices of the first to fifth embodiments, respectively.

For example, a load variation unit 5001 described below can be used as one of a plurality of partial load variation units 5001a, 5001b, and 5001c in the load variation unit 953 in FIG. Further, a load variation unit 5001 described below may be used as it is as the load variation unit 953 in FIG.
Note that the shunt circuit refers to a circuit branched from a certain circuit, and in this embodiment, refers to a circuit branched from the transmission line 5011 (or transmission line 5012). One end of the shunt circuit provided in the transmission line 5011 (or the transmission line 5012) is connected to the transmission line 5011 (or the transmission line 5012). The other end of the shunt circuit is connected to the ground, for example. The other end of the shunt circuit may be open.

[6.17.1 First Example]
FIG. 45 shows a first example of a load changing unit 5001 in which the impedance is changed by a shunt circuit provided in the transmission line.

The load changing unit 5001 includes a plurality (two) of transmission lines 5011 and 5012 connected in parallel.
The first transmission line 5011 and the second transmission line 5012 are each configured by a microstrip line (or strip line). The transmission lines 5011 and 5012 shown in FIG. 45 are both λ / 4 transmission lines (transmission lines having a line length of λ / 4). However, since a shunt circuit (first shunt circuit) 5030 is connected to the center in the length direction of the second transmission line 5012, in FIG. 45, for convenience, λ / 8, which is half the length of λ / 4. One second transmission line 5012 is expressed by drawing two transmission lines.

As described above, the shunt circuit 5030 configured to be able to change the impedance is provided in the middle of the second transmission line 5012 in the length direction (the center position in the length direction in FIG. 45). The first transmission line 5011 is not provided with a shunt circuit.
In addition, the shunt circuit 5030 should just be provided in the length direction middle position of the 2nd transmission line 5012, and does not need to be a length direction center position. However, the circuit design is facilitated by setting the shunt circuit 5030 to the center position in the length direction.

  In FIG. 45, a shunt circuit 5030 provided in the middle of the transmission line 5012 in the length direction is configured as a variable reactance circuit (a circuit whose reactance is variable). In FIG. 45, the variable inductor L is shown as an element (control element) included in the shunt circuit 5030. The value (element state) of the inductance (inductive reactance) of the variable inductor L changes according to a control signal given to the variable inductor L.

  The variable inductor L is not limited to a single element that directly changes inductance (inductive reactance) like a variable coil, and may be any circuit equivalent to such an element. It may be a circuit composed of a plurality of elements (including control elements) configured to change the reactance (details will be described later).

  When the impedance L of the shunt circuit 5030 is changed in a range from 0 to infinity (∞) as shown in FIG. 46A, for example, the impedance of the load changing unit 5001 is as shown in FIG. 46B. It changes to draw an arc on the Smith chart.

Here, in the circuit of FIG. 45, the impedance L of the shunt circuit 5030 being 0 or ∞ corresponds to the switching element (control element) 5021 being turned ON or OFF in the circuit of FIG. .
That is, L = ∞ is equivalent to a circuit equivalent to the switching element 5021 in FIG. 33A being in a non-conduction state (OFF). Accordingly, the impedance of the load change unit 5001 shown in FIG. 45, line impedance of the first transmission line 5011 (characteristic impedance) line impedance of _{Z 1} and the second transmission line 5012 (characteristic impedance) combined impedance of _{Z 2 (Z} 1 / / Z ₂ ) (see FIG. 33B).

For example, if Z ₁ = Z ₂ = Z ₀ = 50 [Ω], the overall characteristic impedance (synthetic impedance) of the plurality of transmission lines 5011 and 5012 connected in parallel is 25 [Ω]. Z ₀ is a value (normalized impedance = 1) for impedance matching with a circuit (for example, an antenna) to which a signal output from the load changing unit is given. Impedance matching means power matching.

  Therefore, when the impedance L of the shunt circuit 5030 is ∞, the impedance of the load changing unit 5001 shown in FIG. 45 is 25 [Ω], which is equal to the overall characteristic impedance of the plurality of transmission lines 5011 and 5012 connected in parallel. It becomes.

  On the other hand, L = 0 is equivalent to a circuit equivalent to the switching element 5021 in FIG. 33A being in the conductive state (ON). Therefore, the impedance of the load changing unit 5001 shown in FIG. 45 is the combined impedance of the π-type circuit shown in FIG.

  As described above, the load changing unit 5001 in FIG. 45 conceptually includes the load changing unit 5001 in FIG. In other words, the load changing unit 5001 in FIG. 33A is equivalent in circuit to that in which the impedance L of the shunt circuit 5030 of the load changing unit 5001 in FIG. 45 takes only two values of 0 or ∞ discretely. is there.

The impedance variable range F shown in FIG. 46B starts from a point P1 where L = ∞, passes through a point P3 (center of Smith chart) where the normalized impedance is 1, and a point P2 where L = 0. Draw a trajectory on the arc leading to. Considering a circle including an arc passing through the points P1, P3, P2 (the center of the circle is C1), the radius of the circle is 0.5 (the radius of the Smith chart (outermost circle) is 1). If).
Incidentally, the impedance of the load change unit 5001, the impedance of the shunt circuit 5030 may become the point P3 is set to _{L a.}

45, in order to increase the variable range F of the impedance, the characteristic impedance Z ₂ of the second transmission line 5012 provided with the shunt circuit 5030 is changed to the characteristic impedance Z ₁ of the first transmission line 5011. Larger than that. The larger the Z _2, it is possible to increase the variable range F of the impedance of the load change unit 5001.
Therefore, by setting Z ₂ > Z ₁ , the variable range F of the impedance of the load changing unit 5001 in FIG. 45 can be made larger than the variable range F shown in FIG. That is, by setting Z ₂ > Z ₁ , the position of P2 in FIG. 46 is moved outside the Smith chart along the arc centered at the point C1, and the arc indicating the variable range F is lengthened. Can do.

Note that in order to satisfy Z ₂ > Z ₁ , the width of the second transmission line (microstrip line or strip line) 5012 is made larger than that of the first transmission line (micro strip line or strip line) 5011 as shown in FIG. You can also make it thinner.

46B, the locus from the point P1 to the point P3 in the variable impedance range F is located on the real axis R or in the vicinity of the real axis R, and the portion E changing along the real axis R. It has become.
Here, in order to appropriately perform load modulation, it is preferable that the impedance (input impedance) of the load fluctuation unit 5001 has only a resistance component or a small amount even if there is a reactance component, and the resistance component is dominant. .

Therefore, when the impedance of the load changing unit 5001 is changed within the range of the portion E (the range from the point P1 to the vicinity of the point P3), the impedance of the load changing unit 5001 has a small reactance component and a dominant resistance component. It will change while maintaining the state.
Regarding the impedance of the load change unit 5001, “the resistance component is dominant” means that R / X> 1 when the impedance is expressed as Z = R + iX (R is a resistance component and X is a reactance component). State. That is, the resistance component is larger than the reactance component. In this state, it is considered that there is substantially no reactance component in the impedance. Within the range of the portion E (range from the point P1 to the vicinity of the point P3), the resistance component is dominant.
Further, a more preferable state where the “resistance component is dominant” is R / X ≧ 1.5, and more preferably R / X ≧ 2.

In order to change the impedance of the load changing unit 5001 within the range of the part E (continuously or discretely), the impedance L of the shunt circuit 5030 is changed from L = L _a (or _a value in the vicinity of La) to L = It may be changed (continuously or discretely) within a range up to ∞.
In this way, when the impedance of the load variation unit 5001 is changed while maintaining the state in which the resistance component is dominant, the resistance value is changed while the state in which the load variation unit 5001 appears to be substantially resistance is maintained. Can be made.
In addition, in FIG. 46B, the reactance component included in the impedance of the load changing unit 5001 can be made zero at the two points P1 and P3. In addition, within the range of the portion E, the impedance can be changed within a range where it can be considered that the reactance component is substantially absent.

An impedance conversion unit (auxiliary impedance conversion unit) 5002 is connected to the input side of the load variation unit 5001 shown in FIG. 45, similarly to the load variation unit 5001 in FIG. The impedance converter 5002 is configured by a λ / 4 transmission line. 45 has the same function as that of the impedance converter 850 in the amplification device 801 shown in FIG.
Therefore, for example, when the impedance variable range of the load changing unit 5001 is as shown in FIG. 46B, by providing the impedance conversion unit 5002, normalized impedance = 1 (see FIG. 46C). For example, the impedance can be varied in the range of 50Ω or more.

[6.17.2 Second Example]
FIG. 47 shows a second example of a load changing unit 5001 whose impedance changes due to a shunt circuit provided in the transmission line.
47 is the same as the load fluctuation unit 5001 shown in FIG. 45 except that it additionally includes a shunt circuit (second shunt circuit) 5040 connected to the first transmission line 5011. The load fluctuation unit 5001 shown in FIG. It has a configuration. In FIG. 47, the impedance conversion unit 5002 is not shown, but the impedance conversion unit 5002 can also be connected to the load fluctuation unit 5001 in FIG.

The first shunt circuit 5030 of the second transmission line 5012 has a variable inductor L2, whereas the second shunt circuit 5040 of the first transmission line 5011 has a fixed value inductor L1 instead of being variable. Yes.
That is, the second shunt circuit 5040 is a circuit that includes the element L1 whose element state does not change, but does not include the element whose element state changes.
Note that the second shunt circuit 5040 is also provided at the center in the length direction of the first transmission line 5011 as in the case of the first shunt circuit 5030. It may be the position.

The second shunt circuit 5040 is for adjusting the impedance variable range F of the load changing unit 5001. That is, the second shunt circuit is a circuit for adjusting the impedance variable range.
FIG. 48 shows the impedance variable range F of the load changing unit 5001 when the value of the variable inductor L2 is changed from 0 to infinity for each of the six types of values set for the inductor L1. ing.
48, the characteristic impedances Z ₁ and Z ₂ of the first transmission line 5011 and the second transmission line 5012 in FIG. 47 are set to Z ₀ (normalized impedance = 1) in order to obtain the result shown in FIG. it may be another value other than Z _0.

48, the value of L1 is set to “0” (see FIG. 48A), “16.25i” (see FIG. 48B), “36.3i” (see FIG. 48C), “ 68.8i ”(see FIG. 48 (d)),“ 154i ”(see FIG. 48 (e)), and“ ∞ ”(see FIG. 48 (f)) were set. As shown in FIG. 48, as the value of L1 increases, the impedance variable range F of the load changing unit 5001 moves in the clockwise direction along a circle (radius 0.5) centered on the point C1. .
Note that when L1 = ∞, the circuit is equivalent to the load changing unit 5001 in FIG.

In this way, by setting the value of L1 according to the desired impedance variable range F, the desired impedance variable range F can be obtained.
In the second example shown in FIG. 47 as well, as in the first example shown in FIG. 45, the variable range F of impedance can be widened by setting Z ₂ > Z ₁ .

[6.17.3 Third Example]
FIG. 49A shows a third example of the load changing unit 5001 in which the impedance is changed by a shunt circuit provided in the transmission line.
In the load changing section 5001 shown in FIG. 49 (a), the first shunt circuits 5030a and 5030b each having variable inductors L1 and L2 are connected to the plurality (two) of transmission lines 5011 and 5012, respectively. It has become. Other points are the same as those of the load changing unit 5001 shown in FIG. 49, the impedance conversion unit 5002 is not shown, but the impedance conversion unit 5002 can also be connected to the load variation unit 5001 in FIG.

  FIG. 49B shows the variable range F of the impedance of the load changing unit 5001 when each of L1 and L2 of the load changing unit 5001 in FIG. 49A is changed from 0 to ∞. The variable range F in FIG. 49B corresponds to a superposition of all six types of variable ranges F in FIG. As described above, by providing a plurality of first shunt circuits 5030a and 5030b whose impedance can be changed, the variable range F of the impedance of the load changing unit 5001 can be widened (variable range F) compared to the case where the value of L1 is fixed. Can be increased).

The impedance variable range shown in FIG. 49B is obtained by changing the parameters (line lengths θ ₁ and θ ₂ and characteristic impedances Z ₁ and Z ₂ ) of the two transmission lines 5011 and 5012 shown in FIG. This is the same as the case of the two transmission lines 5011 and 5012 of the load changing unit 5001 (line length θ ₁ = θ ₂ = λ / 4 = λ / 8 + λ / 8, characteristic impedance Z ₁ = Z ₂ = Z ₀ ).
Thus, by providing a variable L1, the characteristic impedance _{Z 2} of the second transmission line 5012, it may not be greater than the characteristic impedance _{Z 1} of the first transmission line 5011 _(e.g., Z 1 _{= Z} 2 = even if the Z _0), it is possible to increase the variable range of the impedance of the load change unit 5001.

To increase the characteristic impedance Z ₂ of the second transmission line 5012, it is necessary to thinner the width of the second transmission line 5012, is large variable range of the desired impedance, along therewith, the second transmission It is necessary to reduce the width of the line 5012 sufficiently.
However, it may be difficult to sufficiently reduce the width of the second transmission line 5012 due to processing restrictions on the substrate on which the second transmission line 5012 is formed.
For this reason, it may be difficult to obtain a desired variable range of impedance only by reducing the width of the second transmission line 5012.

However, since the variable range can be increased also by providing the variable L1, it is desirable even when Z ₁ = Z ₂ or when Z ₂ > Z ₁ but Z ₂ is not so large. The variable range of impedance can be easily obtained.

In FIG. 50, in the third example, the characteristic impedances Z ₁ and Z ₂ of the transmission lines 5011 and 5012 are fixed to Z ₀ (= 50Ω), and the line lengths θ ₁ and θ ₂ of the transmission lines 5011 and 5012 are changed. Shows the case.
As shown in FIG. 50A, the line lengths θ ₁ and θ ₂ of the transmission lines 5011 and 5012 are θ ₁ = θ ₂ = θ, and θ is 0.1 (electrical length) to 0.5 (electrical length). In the range of (long), the step size was changed at 0.05.

  As shown in FIG. 50B, when θ = 0.25 (λ / 4), the variable range of the load changing unit 5001 is the same as the variable range F shown in FIG. It becomes the center arc. When θ becomes larger than 0.25 (λ / 4), the center C1 of the arc moves clockwise CW on the Smith chart. On the other hand, when θ is smaller than 0.25 (λ / 4), the center C1 of the arc moves counterclockwise CCW on the Smith chart.

  Thus, even if the line length θ of the transmission lines 5011 and 5012 is set to a length other than 0.25 (λ / 4), only the position of the variable range (the center of the arc) changes, and the line length θ As in the case of = 0.25 (λ / 4), the impedance of the load changing unit 5001 can be made variable. Even if the line length θ is changed, the size of the variable range can be maintained.

As is apparent from FIG. 50B, even if the line length θ of the transmission lines 5011 and 5012 is changed, the impedance variable range always passes through the center of the Smith chart (normalized impedance = 1).
Therefore, even if the line length θ of the transmission lines 5011 and 5012 is changed, if L1 and L2 are appropriately set, the impedance of the load changing unit 5001 can be changed to a circuit (for example, a signal output from the load changing unit 5001) , Antenna) can be set to a value (for example, 50Ω) that matches the impedance.

Further, as apparent from FIG. 50B, even when the line length θ of the transmission lines 5011 and 5012 is changed, the point P2 where L ₁ = L ₂ = 0 is a position on the outermost circle of the Smith chart. To maintain.
As described above, as L ₁ and L ₂ are smaller, the impedance of the load variation unit 5001 is more easily positioned on the radially outer side of the Smith chart. On the other hand, as L ₁ and L ₂ are larger, the center or the real axis of the Smith chart is used. It becomes easy to be located in the vicinity of R.
Therefore, from the viewpoint of changing the impedance of the load changing unit 5001 while maintaining the state in which the resistance component is dominant, it is preferable to change L ₁ and L ₂ in a range of as large a value as possible.

51, in the third example, the line lengths θ ₁ and θ ₂ of the transmission lines 5011 and 5012 are fixed to θ = 0.25 (λ / 4), and the characteristic impedances Z ₁ and Z _{2 of the} transmission lines 5011 and 5012 are fixed. The case where is changed is shown.
As shown in FIG. 51A, the characteristic impedances Z ₁ and Z ₂ of the transmission lines 5011 and 5012 are Z ₁ = Z ₂ = Z, and Z changes with a step size = 10 in the range of 30Ω to 80Ω. I let you.

As shown in FIG. 51 (b), when Z = 50Ω (= Z ₀ ), the variable range of the load changing unit 5001 is the same as the variable range F shown in FIG. 49 (b), with the point C1 as the center. Arc. When Z becomes larger than 50Ω, the center C1 of the arc moves clockwise CW on the Smith chart. However, the point P1 where L1 = L2 = ∞ maintains the position of the real axis R. When Z becomes larger than 50Ω, the point P1 approaches the center of the Smith chart (normalized impedance = 1).
On the other hand, when Z becomes smaller than 50Ω, the arc center C1 moves counterclockwise CCW on the Smith chart. However, the point P1 where L1 = L2 = ∞ maintains the position of the real axis R. When Z becomes smaller than 50Ω, the point P1 moves away from the center of the Smith chart (normalized impedance = 1).

As shown in FIG. 51B, even if the characteristic impedance Z of each of the transmission lines 5011 and 5012 is set to a value other than 50Ω, only the position of the variable range (the center of the arc) changes, and Z = 50Ω. Similarly to a certain case, the impedance of the load changing unit 5001 can be made variable.
As is clear from FIG. 51B, even if the characteristic impedance Z of each of the transmission lines 5011 and 5012 is changed, the variable impedance range always passes through the center of the Smith chart (normalized impedance = 1).
Therefore, even if the characteristic impedance Z of the transmission lines 5011 and 5012 is changed, if L1 and L2 are appropriately set, the impedance of the load changing unit 5001 is changed to a circuit to which a signal output from the load changing unit 5001 is given (for example, , Antenna) can be set to a value (for example, 50Ω) that matches the impedance.

Moreover, as shown in FIG. 51B, even if the characteristic impedance Z of the transmission lines 5011 and 5012 is changed, the impedance of the load changing unit 5001 can be set to an arbitrary value on the real axis R if L1 and L2 are set to ∞. Values (0Ω to 50Ω) can be taken.
That is, when L1 and L2 are set to ∞, the impedance of the load changing unit 5001 is a combined impedance of the line impedance (characteristic impedance) Z of the first transmission line 5011 and the line impedance (characteristic impedance) Z of the second transmission line 5012 ( Z // Z) (see FIG. 33B). Since the transmission lines 5011 and 5012 have only a resistance component if the line length is λ / 4, the combined impedance (Z // Z) also has only a resistance component (substantially no reactance component exists).

Further, as apparent from FIG. 51B, even when the characteristic impedance Z of the transmission lines 5011 and 5012 is changed, the point P2 where L ₁ = L ₂ = 0 is a position on the outermost circle of the Smith chart. To maintain.
As described above, as L ₁ and L ₂ are smaller, the impedance of the load variation unit 5001 is more easily positioned on the radially outer side of the Smith chart. On the other hand, as L ₁ and L ₂ are larger, the center or the real axis of the Smith chart is used. It becomes easy to be located in the vicinity of R.
Therefore, from the viewpoint of changing the impedance of the load changing unit 5001 while maintaining the state in which the resistance component is dominant, it is preferable to change L ₁ and L ₂ in a range of as large a value as possible.

In addition, when the line lengths of the transmission lines 5011 and 5012 are λ / 4, the locus of the variable range from the point P1 where L1 = L2 = ∞ to the vicinity of the center position of the Smith chart is on the real axis R or A portion E is located near the real axis R and varies along the real axis R (particularly, the point P1 is located on the real axis R).
Therefore, when the line lengths of the transmission lines 5011 and 5012 are λ / 4, by changing L ₁ and L ₂ in a relatively large value range, the impedance of the load changing unit 5001 can be reduced by the resistance component. It becomes easy to change while maintaining the dominant state.

Further, according to FIG. 51 (b), a circuit (for example, a circuit in which the overall characteristic impedance (Z // Z) of the plurality of transmission lines 5011 and 5012 connected in parallel is given by the signal output from the load changing unit 5001 (for example, , Antenna) is smaller than a value matching impedance (for example, 50Ω), it can be seen that a portion where the locus of the variable range of the impedance of the load changing unit 5001 changes along the real axis R becomes wider.
For example, if Z ₁ = Z ₂ = Z = 30Ω, then (Z // Z) = 15Ω, and if Z ₁ = Z ₂ = Z = 80Ω, then (Z // Z) = 40Ω, Each value in the change range of Z illustrated in 51 (range of 30Ω to 80Ω) indicates that the overall characteristic impedance (Z // Z) of the plurality of transmission lines 5011 and 5012 connected in parallel is output from the load fluctuation unit 5001. This value is smaller than a value (in this case, 50Ω) that matches the impedance of a circuit (for example, an antenna) to which the signal to be applied is applied.

And, as the value of Z ₁ = Z ₂ = Z is smaller, the portion E changing along the real axis R becomes wider. Therefore, in order to widen the portion E changing along the real axis R, the transmission line 5011, What is necessary is just to make the width of 5012 wide. Therefore, in order to widen the portion E that changes along the real axis R, it is not necessary to reduce the width of the transmission lines 5011 and 5012, which causes problems in processing the substrate when the width of the transmission line is reduced. Can be avoided.

[6.17.4 Fourth Example]
FIG. 52A shows a fourth example of the load changing unit 5001 in which the impedance is changed by a shunt circuit provided in the transmission line.
In the load fluctuation section 5001 shown in FIG. 52A, the number of transmission lines 5011, 5012, 5013 connected in parallel is three. That is, the load changing unit 5001 shown in FIG. 52A adds the third transmission line 5013 to the load changing unit 5001 shown in FIG. 49A, and the first shunt circuit 5030c (variable inductor) is added to the third transmission line 5013. L3) is added.
Other points are the same as those of the load changing unit 5001 shown in FIG. 52, the impedance conversion unit 5002 is not shown, but the impedance conversion unit 5002 can also be connected to the load variation unit 5001 in FIG.

  The variable range F of the impedance of the load changing unit 5001 shown in FIG. 52A can take the same variable range as FIG. 49B as shown in FIG. 52B under a predetermined condition. That is, the load changing unit 5001 shown in FIG. 52A can be equivalent in circuit to the load changing unit 5001 shown in FIG.

Here, when the number of parallel connection of the transmission line of the load changing unit 5001 is n, the conditions for being equivalent to the load changing unit 5001 having the number of parallel connection of the transmission line are as follows.
Zthn / n = Zthm / m
here,
Zthn: characteristic impedance of each transmission line when the number of parallel connections of transmission lines is n Zthm: characteristic impedance of each transmission line when the number of parallel connections of transmission lines is m

Therefore, considering the case where n is 3 as shown in FIG. 52 and m is 2 as shown in FIG. 49, Z ₁ = Z ₂ = Zth2 in the load fluctuation section 5001 of FIG. And when
Zth3 / 3 = Zth2 / 2
52, the load fluctuation unit 5001 in FIG. 52 and the load fluctuation unit 5001 in FIG. 49 are equivalent in circuit.
For example, when Zth3 = 45Ω and Z ₁ = Z ₂ = Zth2 = 30Ω, or when Zth3 = 75Ω and Z ₁ = Z ₂ = Zth2 = 50Ω, the load variation unit 5001 in FIG. 49 is equivalent to the load fluctuation unit 5001 in FIG.

  Therefore, the above-described consideration regarding the load changing unit 5001 according to the third example also applies to the load changing unit 5001 according to the fourth example of FIG.

Even when three or more transmission lines 5011, 5012, and 5013 are provided as in the load changing unit 5001 shown in FIG. 52, the shunt circuits (first shunt circuits) 5030a, 5030b, and 5030c include at least one transmission line 5011. , 5012, 5013 may be provided. However, the number of shunt circuits (first shunt circuits) is preferably two or more.
In the load changing unit 5001 shown in FIG. 52, at least one of the plurality of shunt circuits may be a shunt circuit (second shunt circuit) that does not have a variable element.

[6.17.5 Fifth Example]
FIG. 53A shows a fifth example of the load changing unit 5001 in which the impedance is changed by a shunt circuit provided in the transmission line.
53A includes a single transmission line 5011 that is not connected in parallel, and a first shunt circuit 5030 (variable inductor L) is provided on the transmission line 5011. The load fluctuation unit 5001 illustrated in FIG. It has been.
Other points are the same as those of the load changing unit 5001 shown in FIGS. 49 (a) and 52 (a). 53 does not show the impedance conversion unit 5002, the impedance conversion unit 5002 can also be connected to the load variation unit 5001 in FIG.

  53 (a) can also take the same variable range as shown in FIG. 49 (b) and FIG. 52 (b) as shown in FIG. 53 (b) under predetermined conditions. That is, the load changing unit 5001 shown in FIG. 53A can be equivalent in circuit to the load changing unit 5001 shown in FIGS. 49A and 52A.

That is, the aforementioned Zthn / n = Zthm / m
The above relational expression holds even when the number of transmission lines of the load changing unit 5001 is 1 (the number of parallel connections is 1).
Therefore, consider the case where n is 1 as shown in FIG. 53 (a) and m is 3 in FIG. 52 (a).
Zth1 / 1 = Zth3 / 3
Is established, the load fluctuation unit 5001 in FIG. 53A and the load fluctuation unit 5001 in FIG. 52A are equivalent in circuit.
For example, when Zth1 = 15Ω and Zth3 = 45Ω, or when Zth1 = 25Ω and Zth3 = 75Ω, the load variation unit 5001 in FIG. 53A and the load variation unit in FIG. 5001 is equivalent in circuit.

  Therefore, the above-described consideration regarding the load variation unit 5001 according to the third example that can be equivalent to the load variation unit 5001 according to the fourth example also applies to the load variation unit 5001 according to the fifth example in FIG.

  53, the number of transmission lines 5011 from the signal input side (IN) to the signal output side (OUT) in the load variation unit is one (the number of parallel connections = 1). Therefore, the circuit configuration can be simplified, which is preferable.

54, in the load changing unit 5001 shown in FIG. 53, the characteristic impedance Zth1 of the transmission line 5011 is set to a value Z ₀ that impedance matches with a circuit (for example, an antenna) to which a signal output from the load changing unit 5001 is applied. Shows the case. In this case, the variable impedance range F of the load changing unit 5001 is as shown in FIG.

  In the impedance variable range F shown in FIG. 54B, the point P1 where L = ∞ is the point where the normalized impedance is 1 (the center of the Smith chart). The variable range F is an arc along a circle (radius = 0.5) passing through the center of the Smith chart. The variable range F starts from the point P1 and reaches the point P2 where L = 0. In the case of the point P2 (L = 0), the impedance of the load changing unit 5001 is ∞.

As shown in FIG. 54, when the characteristic impedance Zth1 of only one transmission line 5011 is set to Z ₀ (for example, 50Ω), this load variation unit 5001 is used as a load variation unit (load variation unit) in a load modulation type amplification device. When used as, the efficiency of the amplification device may be reduced.

Here, in the load modulation system, when the signal input to the amplifying device is small, and therefore the signal output from the load fluctuation unit 5001 is also desired to be small, the reflection of the signal at the load fluctuation unit 5001 may be increased.
On the other hand, when the signal input to the amplifying device is large and therefore the signal output from the load changing unit 5001 is also desired to be increased, the reflection of the signal at the load changing unit 5001 may be reduced.

However, if the characteristic impedance Zth1 of the transmission line 5011 is Z ₀ (for example, 50Ω), when considering only the transmission line 5011 (assuming that the impedance of the shunt circuit 5030 is infinite), the load fluctuation The reflection at the unit 5001 is minimized, and the signal output from the load changing unit 5001 is maximized (loss is small).

Therefore, when it is desired to increase the reflection at the load changing unit 5001 and reduce the signal output from the load changing unit 5001, the reactance is set so that the impedance of the load changing unit 5001 is a value other than Z ₀ (the center of the Smith chart). Ingredients are required.
That is, when it is desired to obtain a low power signal from the load changing unit 5001, the impedance of the shunt circuit 5030 is not infinite, but needs to be a value L smaller than infinity.
As a result, when it is desired to reduce the signal output, the impedance of the shunt circuit 5030 is reduced, and a wasteful current easily flows through the shunt circuit 5030.
When the current flowing through the shunt circuit 5030 is large, the efficiency of the amplifying device is lowered.

Here, in the case of a communication method such as W-CDMA and OFDM where peak power occurs only rarely and the ratio of average power to peak power is large, the loss of small power signals that occur probabilistically is small. It is desirable.
However, as shown in FIG. 54, when the characteristic impedance Zth1 of only one free transmission line 5011 to Z _0, only occurs stochastically rare only loss of the high-power signal is decreased, stochastically many occurrence Loss of the small power signal to be increased. As a result, the efficiency of the amplification device decreases.
Incidentally, this is the overall characteristic impedance of the plurality of transmission lines 5011,5012,5013 connected in parallel (the combined impedance) is also the case is _{Z 0.}

In contrast, when the characteristic impedance Zth1 of only one free transmission line 5011 is Z ₀ a value other than (a value that does not impedance matching), it is possible to prevent deterioration of efficiency of the amplifier.
Here, impedance matching refers to power matching as described above, and a value that does not match impedance refers to an impedance value at which output power is reduced by 2 dB or more compared to power matching (impedance matching). Such impedance values can be measured by calculation or by a measuring instrument called a load pull device.

When the characteristic impedance Zth1 of the transmission line 5011 is a value that does not match the impedance, when only the transmission line 5011 is considered, that is, when the impedance of the shunt circuit 5030 is infinite, reflection at the load fluctuation unit 5001 increases. The signal output from the load fluctuation unit 5001 becomes small.
At this time, since the impedance of the shunt circuit 5030 is infinite, no loss current flows in the shunt circuit 5030.
Therefore, if the characteristic impedance Zth1 of the transmission line 5011 is a value that does not match the impedance, a low-power signal that is frequently generated can be generated with L = ∞ with little loss. As a result, the loss for the low-power signal that is frequently generated is reduced. Therefore, it is possible to prevent a decrease in efficiency of the amplification device.
Incidentally, this is the overall characteristic impedance of the plurality of transmission lines 5011,5012,5013 connected in parallel (the combined impedance) is also the case is a value other than _{Z 0.}

The operation of the amplifying device 951 will be described with reference to FIG. The load control unit 954c in FIG. 42 may control the control element (variable inductor) of the shunt circuit 5030 (5030a, 5030b, 5030c) based on the amplitude information r of the input signal.
In the load control unit 954c, the impedance L of the shunt circuit 5030 (5030a, 5030b, 5030c) increases as the amplitude of the input signal decreases, and the shunt circuit 5030 (5030a, 5030b, 5030c) increases as the amplitude of the input signal increases. What is necessary is just to control so that the impedance L may become small.
Thereby, when the amplitude of the input signal is small, the reflection of the load fluctuation unit 5001 becomes large, the output signal of the load fluctuation unit 5001 becomes small, and when the amplitude of the input signal is large, the reflection of the load fluctuation unit 5001 becomes small. As a result, the output signal of the load fluctuation unit 5001 increases.

As described above, the characteristic impedance Zth1 of the transmission line 5011 is to be smaller than _{Z 0} is (overall characteristic impedance of the plurality of transmission lines 5011,5012,5013 connected in parallel (composite impedance), than _{Z 0} If the value is also a small value, it becomes easy to take a wide portion E where the variable range F changes along the real axis R.

That is, the characteristic impedance Zth1 is greater than _{Z 0} of the transmission line 5011 (total of the characteristic impedance of the plurality of transmission lines 5011,5012,5013 connected in parallel (the combined impedance) is larger than _{Z 0)} met However, although the portion E where the variable range F changes along the real axis R can be secured, the portion is along the real axis R on the right side of the center of the Smith chart.
Therefore, when trying to widen the portion E changing along the real axis R, the position of the point P1 where L = ∞ is on the real axis R on the right side of the center of the Smith chart and is close to impedance = ∞. Must be in position.
That is, the characteristic impedance Zth1 of the transmission line 5011 (the total characteristic impedance (synthetic impedance) of the plurality of transmission lines 5011, 5012, and 5013 connected in parallel) must be a value close to ∞ (a very large value).
However, if the characteristic impedance of only one transmission line 5011 is to be set to a very large value, the width of the transmission line 5011 must be made very thin. In addition, when a plurality of transmission lines 5011, 5012, and 5013 are connected in parallel, the transmission line width of each of the transmission lines 5011, 5012, and 5013 must be further reduced.

For this reason, the characteristic impedance Zth1 of the transmission line 5011 (the overall characteristic impedance of the plurality of transmission lines 5011, 5012, and 5013 connected in parallel (synthetic impedance)) is very large from the viewpoint of substrate processing. It is difficult in practice.
As a result, the overall characteristic impedance of the plurality of transmission lines 5011,5012,5013 characteristic impedance Zth1 is a (parallel connection is larger than _{Z 0} of the transmission line 5011 (a combined impedance) is greater than _{Z 0} Value), it is difficult to widen the portion E where the variable range F changes along the real axis R.

On the other hand, reducing the characteristic impedance Zth1 of the transmission line 5011 (the overall characteristic impedance (synthetic impedance) of the plurality of transmission lines 5011, 5012, and 5013 connected in parallel) only requires increasing the width of the transmission line. Therefore, there are few problems in processing the substrate.
Therefore, the overall characteristic impedance of the plurality of transmission lines 5011,5012,5013 characteristic impedance Zth1 is that is a small value (parallel connection than _{Z 0} of the transmission line 5011 (a combined impedance) is less than _{Z 0} This is preferable because the variable range F can be easily widened in the portion E where the variable range F changes along the real axis R.

Further, in the load changing unit 5001, since the portion excluding the shunt circuit 5030, that is, the transmission line 5011 is a λ / 4 transmission line, when L = ∞, the impedance (point P1) of the load changing unit 5001 is Located on the real axis R of the Smith chart. That is, when L = ∞, the impedance of the load changing unit 5001 does not substantially include reactance, and the resistance component has a dominant value.
Therefore, when the line length of the transmission line 5011 is λ / 4, the impedance of the load changing unit 5001 is maintained in a state where the resistance component is dominant by changing L within a relatively large value range. It becomes easy to change.

  Note that the circuit configuration of the load variation unit 5001 according to the fifth example corresponds to a generalized circuit configuration of the load variation unit 5001 according to the third and fourth examples, and thus the load variation unit according to the fifth example. The above-described consideration regarding 5001 may also apply to the load changing unit 5001 according to the third and fourth examples.

[6.17.6 Circuit of Load Fluctuation Section of Third Example (Pattern 1)]
FIG. 55 shows an example of a circuit for discretely changing each of L1 and L2 of the load variation unit 5001 of the third example shown in FIG.
In FIG. 55, the line lengths of the first transmission line 5011 and the second transmission line 5012 are each λ / 4. The widths of the first transmission line 5011 and the second transmission line 5012 are set to be the same, and the characteristic impedance of both the transmission lines 5011 and 5012 is, for example, 50Ω.

  In FIG. 55, the first shunt circuit 5030a provided in the second transmission line 5012 is configured such that the impedance (inductive reactance) of the first shunt circuit 5030a can be discretely changed to four values. The first shunt circuit 5030b provided in the first transmission line 5012 is configured to be able to discretely change the impedance (inductive reactance) of the first shunt circuit 5030b to two values.

  In FIG. 55, the first shunt circuit 5030a provided in the second transmission line 5012 includes a first line 5056, a second line 5057, a third line 5058, and two switching elements (high-frequency switching elements; control elements). 5021b (D2) and 5021c (D3). Each of the lines 5056, 5057, 5058 is configured as a microstrip line or a strip line. A switching element, which is a control element whose element state is changed by a control signal, can be configured by a PIN diode, for example, and can be switched to a conductive state or a non-conductive state according to the control signal.

The first line 5056 is provided in the middle of the second transmission line 5012 in the length direction (center position in the length direction).
The second line 5057 is connected in series to the first line 5056 via the switching element 5021b (D2). The third line 5058 is connected in series to the first line 5056 via the switching element 5021c (D3). That is, the second line 5057 and the third line 5058 connected in parallel are connected in series to the first line 5056 via the switching elements 5021b (D2) and 5021c (D3).
In the second line 5057 and the third line 5058, ends opposite to the switching elements 5021b (D2) and 5021c (D3) are open.

In FIG. 55, the first shunt circuit 5030b provided in the first transmission line 5011 includes a first line 5061 and one switching element (high frequency switching element; control element) 5021a (D1). The first line 5061 is configured as a microstrip line or a strip line. The switching element which is a control element can be constituted by, for example, a PIN diode, and can be switched to a conductive state or a non-conductive state.
The first line 5061 is connected to the middle of the first transmission line 5011 in the length direction (the center position in the length direction) via the switching element 5021a (D1). In the first line 5061, the end opposite to the switching element 5021a (D1) is open.

  In FIG. 56, switching element 5021b (D2) and switching element 5021c (D3) are switched to ON (conductive state) / OFF (non-conductive state) while switching element 5021a (D1) is OFF (non-conductive state). 4 shows an equivalent circuit for four patterns.

As shown in FIG. 56, when D2 = OFF / D3 = OFF (see FIG. 56 (a)), the load changing unit 5001 includes the second transmission line in addition to the two transmission lines 5011 and 5012 connected in parallel. 5012 is provided with an open stub composed of the first line 5056.
Similarly, when D2 = ON / D3 = OFF (see FIG. 56 (b)), the load changing unit 5001 is connected to the second transmission line 5012 in addition to the two transmission lines 5011 and 5012 connected in parallel. An open stub composed of a line 5056 and a second line 5057 is provided.
Similarly, when D2 = OFF / D3 = ON (see FIG. 56 (c)), the load changing unit 5001 is connected to the second transmission line 5012 in addition to the two transmission lines 5011 and 5012 connected in parallel. An open stub composed of a line 5056 and a third line 5058 is provided.
Similarly, when D2 = ON / D3 = ON (see FIG. 56 (d)), the load changing unit 5001 is connected to the second transmission line 5012 in addition to the two transmission lines 5011 and 5012 connected in parallel. An open stub composed of a line 5056, a second line 5027, and a third line 5058 is provided.

As described above, when the switching element 5021b (D2) and the switching element 5021c (D3) are switched on / off by the control signal, four types of open stubs having different line lengths or line forms are obtained.
Therefore, the first shunt circuit 5030a provided in the second transmission line 5012 has four types of impedance (inductive reactance) Z _a1 , by switching ON / OFF of the switching element 5021b (D2) and the switching element 5021c (D3). Z _a2 , Z _a3 , and Z _a4 can be changed.

  Here, when the switching element 5021a (D1) is OFF (non-conducting state), the variable impedance range of the load changing unit 5001 is the same as in the case of L1 = ∞ in FIG. Therefore, the four types of impedance obtained by switching ON / OFF of the switching element 5021b (D2) and the switching element 5021c (D3) are all within the variable range F in the case of L1 = ∞ in FIG. It becomes the value of.

  In FIG. 57, the switching element 5021b (D2) and the switching element 5021c (D3) are switched to ON (conducting state) / OFF (non-conducting state) while the switching element 5021a (D1) is turned on (conducting state). An equivalent circuit for four patterns is shown.

When the switching element 5021a (D1) is ON (conducting state), the first transmission line 5011 is provided with an open stub composed of the first line 5061.
Therefore, the equivalent circuit shown in FIG. 57 is obtained by providing an open stub including the first line 5061 in the first transmission line 5011 in the equivalent circuit shown in FIG.

Here, it is assumed that the switching element 5021a (D1) is turned on (conducting state) and the first transmission line 5011 is provided with an open stub including the first line 5061 in FIG. 48, except for L1 = ∞. It is equivalent to making the value of L1 of
That is, when the switching element 5021a (D1) is turned on (conductive state), the impedance variable range F changes compared to when the switching element 5021a (D1) is OFF (non-conductive state).

Therefore, as shown in FIG. 58, when the switching element 5021a (D1) is turned on (conducting state), the impedance values Z _b1 , Z _b2 , Z _b3 , and Z _b4 of the load changing unit 5001 are changed to the switching element 5021a ( It changes compared to impedance values Z _a1 , Z _a2 , Z _a3 , and Z _a4 when D1) is OFF (non-conducting state).

Therefore, by switching ON / OFF of the switching element 5021a (D1), the switching element 5021b (D2), and the switching element 5021c (D3) by a control signal from the load control unit 954c, the impedance is changed to a total of eight types of impedance. Can do.
Incidentally, line length _{D L} of the first line 5061, lambda / 4 or lambda / 4 around the length of the _{(e.g., λ / 4 ≦ D L ≦} 3λ / 8) is preferably.

[6.17.7 Circuit of Load Fluctuation Section of Third Example (Pattern 2)]
FIG. 59 shows another circuit example for discretely changing L1 and L2 of the load variation unit 5001 of the third example shown in FIG.
59, the configuration of the first shunt circuit 5030b provided in the first transmission line 5011 is different from that of the load variation unit 5001 in FIG. 55, but the other configurations are the same as those in FIG. is there.

The circuit example of FIG. 59 can reduce the loss more than the circuit example of FIG.
In the circuit of Figure 55, when the switching element 5021a (D1) is in a conductive state, so that the open stub line length _{D L} in the first transmission line 5011 is provided. When the line length _{D L} of the first line 5061 is connected to the first transmission line 5011 (open stub) is the length of around lambda / 4 includes a first transmission line 5011 between the first line 5061 The connection position (the position of the switching element 5021a (D1)) is short.
Therefore, when the switching element 5021a (D1) is in a conductive state, short is generated, so that a current easily flows through the switching element 5021a (D1), and a loss occurs due to the current flowing through the switching element 5021a (D1).

However, the first transmission line 5011 has a different magnitude depending on its position, and if the first transmission line 5011 (the switching element 5021a (D1)) is provided at a position where the current is reduced in the first transmission line 5011, the loss is lost. Can be reduced.
However, if the first line 5061 (switching element 5021a (D1)) is provided at a position where the current is reduced in the first transmission line 5011, the degree of freedom in circuit design is reduced.

  Therefore, the circuit example of FIG. 59 is configured so that the loss can be reduced even if the first line 5061 (switching element 5021a (D1)) is provided at a position where the current increases in the first transmission line 5011. Yes.

More specifically, the first shunt circuit 5030b provided in the first transmission line 5011, the first stub 5071 which line length consists lines _{D L,} a second stub 5072 of line length lambda / 4, switching And an element 5021a (D1).
The first stub 5071 is provided at a connection position midway in the length direction (center in the length direction) of the first transmission line 5011. Line length _{D L} of the first stub 5071, lambda / 4 or lambda / 4 around the length of the _{(e.g., λ / 4 ≦ D L ≦} 3λ / 8) is preferably.
In the following, for convenience, the first stub 5071 is connected to the first transmission line 5011 from the connection position of the line length of λ / 4 (first part) 5071a and the remaining part excluding the first part 5071a ( The second part) 5071b may be considered separately. The line length of the second portion is (D _L -λ / 4).
The second stub 5072 is connected midway in the length direction of the first stub 5071 through the switching element 5021a (D1).

When the switching element 5021a (D1) is OFF (non-conductive state), the second stub 5072 is substantially longer exists, the open stub line length (non-conductive state line length) is the first stub 5071 is _{D L} Is connected to the first transmission line 5011. The line length (non-conductive state line length) _{D L} open stub, the load change unit 5001 shown in FIG. 55, the same state as when the switching element 5021a (D1) is ON (conductive state) (see FIG. 57) can get.
Therefore, when the switching element 5021a (D1) is turned off (non-conducting state), the impedance value of the load changing unit 5001 is compared with the impedance value when the switching element 5021a (D1) is on (conducting state). Change.

On the other hand, when the switching element 5021a (D1) is ON, the open stub having the line length λ / 2 by the first portion 5071a of the first stub 5071 and the second stub 5072 is connected to the first transmission line 5011. Become.
Here, since the end of the second stub 5072 opposite to the switching element 5021a (D1) is open, the switching element 5021a (D1) is connected to the second stub 5072. The end portion on the side is short. The second portion 5071b of the first stub 5071 does not function because it is connected in parallel with the second stub 5072 at the position where it is short.

Therefore, when the switching element 5021a (D1) is ON, only the first portion 5071a of the first stub 5071 having the line length λ / 4 and the second stub 5072 having the line length λ / 4 are connected in series. . As a result, the open stub having the line length λ / 2 is connected to the first transmission line 5011.
In the case of an open stub having a line length λ / 2, the connection position between the first stub 5071 and the first transmission line 5011 is also open. Therefore, when viewed from the first transmission line 5011, this is equivalent to the absence of an open stub having a line length λ / 2. With the open stub having the line length λ / 2, the same state (see FIG. 56) as that when the switching element 5021a (D1) is OFF (non-conducting state) is obtained in the load changing unit 5001 shown in FIG.

  As a result, when the switching element 5021a (D1) is turned on (conductive state), the impedance value of the load changing unit 5001 is compared with the impedance value when the switching element 5021a (D1) is OFF (non-conductive state). Change.

59, when the switching element 5021a (D1) is ON, when viewed from the first transmission line 5011, this is equivalent to the absence of an open stub of the line length λ / 2. Therefore, even if the first stub 5071 is provided in a portion where the current is large in the first transmission line 5011, the current flowing to the first stub 5071 is reduced, and the first stub 5071 (open stub having a line length λ / 2) is obtained. Loss due to the current flowing through is also reduced.
Note that the switching element 5021a (D1) is provided at a position that becomes short in the open stub of the line length λ / 2, and is at a position where the current tends to increase. However, since the current flowing through the open stub itself having the line length λ / 2 is small, the current flowing through the switching element 5021a (D1) is also small, and the occurrence of loss in the switching element 5021a (D1) can be suppressed. it can.

  The line length of the open stub obtained when the switching element 5021a (D1) is turned on (conducting state) is not limited to λ / 2, and is (λ / 2) × n (n is an integer of 1 or more). Good. Specifically, the line length of the second stub 5072 is not limited to λ / 4, and may be (λ / 4) + ((λ / 2) × m (m is an integer of 0 or more)).

  Further, the shunt circuit 5030b illustrated in FIG. 59 may be used as the first shunt circuit 5030a connected to the second transmission line 5012.

[6.17.8 Circuit of Load Fluctuation Section of Third Example (Pattern 3)]
FIG. 60 shows another circuit example for discretely changing L1 and L2 of the load variation unit 5001 of the third example shown in FIG.
60, the configuration of the first shunt circuit 5030b provided in the first transmission line 5011 is different from that of the load variation unit 5001 in FIG. 55, but the other configurations are the same as those in FIG. is there.

Similarly to the circuit example of FIG. 59, the circuit example of FIG. 60 can reduce loss more than the circuit example of FIG.
In Figure 60, the first shunt circuit 5030b provided in the first transmission line 5011, the first stub 5073 which line length consists lines _{D L,} line length of _{((λ / 2) -D L} ) first 2 stubs 5074 and a switching element 5021a (D1).

The first stub 5073 is provided at a connection position in the middle of the first transmission line 5011 in the length direction (center in the length direction). Line length _{D L} of the first stub 5073, lambda / 4 or lambda / 4 around the length of the _{(e.g., λ / 4 ≦ D L ≦} 3λ / 8) is preferably.
The second stub 5074 is connected in series to the first stub 5073 via the switching element 5021a (D1). The line length of the second stub 5074 is not limited to ((λ / 2) −D _L ), and may be (((λ / 2) × n) −D _L ) (n is an integer of 1 or more). .

When the switching element 5021a (D1) is OFF (non-conductive state), the second stub 5074 is substantially longer exists, the open stub line length (non-conductive state line length) is the first stub 5073 is _{D L} Is connected to the first transmission line 5011. The line length (non-conductive state line length) _{D L} open stub, the load change unit 5001 shown in FIG. 55, the same state as when the switching element 5021a (D1) is ON (conductive state) (see FIG. 57) can get.
Therefore, when the switching element 5021a (D1) is turned off (non-conducting state), the impedance value of the load changing unit 5001 is compared with the impedance value when the switching element 5021a (D1) is on (conducting state). Change.

On the other hand, when the switching element 5021a (D1) is ON, the open stub having the line length λ / 2 by the first stub 5073 and the second stub 5074 connected in series is connected to the first transmission line 5011. .
In the case of an open stub having a line length λ / 2, the connection position between the first stub 5073 and the first transmission line 5011 is also open. Therefore, when viewed from the first transmission line 5011, this is equivalent to the absence of an open stub having a line length λ / 2. With the open stub having the line length λ / 2, the same state (see FIG. 56) as that when the switching element 5021a (D1) is OFF (non-conducting state) is obtained in the load changing unit 5001 shown in FIG.

  As a result, when the switching element 5021a (D1) is turned on (conductive state), the impedance value of the load changing unit 5001 is compared with the impedance value when the switching element 5021a (D1) is OFF (non-conductive state). Change.

  60, when the switching element 5021a (D1) is ON, when viewed from the first transmission line 5011, it is equivalent to the absence of an open stub having a line length λ / 2. Therefore, even if the first stub 5073 is provided in a portion where the current is large in the first transmission line 5011, the current flowing to the first stub 5073 is reduced, and the first stub 5073 (open stub having a line length λ / 2) is obtained. Loss due to the current flowing through is also reduced.

In addition, in the load variation unit 5001 in FIG. 60, the switching element 5021a (D1) is not provided at a position (short from the open position to λ / 4) in the open stub having the line length λ / 2. In the open stub having the line length λ / 2, the current is provided at a position where the current is relatively small.
Therefore, in the load changing unit 5001 in FIG. 60, it is possible to reduce the loss due to the current flowing through the switching element 5021a (D1), compared to the load changing unit 5001 in FIG.

The shunt circuit 5030b illustrated in FIG. 60 may be used as the first shunt circuit 5030a connected to the second transmission line 5012.
The first shunt circuits 5030a and 5030b shown in FIGS. 55, 59, and 69 are replaced with the first shunt circuit 5030 of the first example shown in FIG. 45 and the first shunt circuit 5030 of the second example shown in FIG. It may be used.

[6.17.9 Circuit Example of First Shunt Circuit with Variable Impedance]
61 to 66 show various variations of the circuit example of the first shunt circuit other than the circuit example of the first shunt circuit already described. In FIGS. 61 and 63 to 65, for ease of understanding, the circuit example of the first shunt circuit 5030 is used for the first shunt circuit 5030 of the load variation unit 5001 of the first example shown in FIG. showed that. However, the circuit examples of the first shunt circuit 5030 shown in FIGS. 61 and 63 to 66 are used as the first shunt circuits 5030a, 5030b, 5030b, and 5030c shown in FIGS. 45, 47, and 49 to 54. Also good.

  The first shunt circuit 5030 shown in FIG. 61 is for operating the first shunt circuit 5030 so that the inductance (inductive reactance) changes by changing the capacitance (capacitive reactance).

Specifically, the first shunt circuit 5030 has a plurality (two) of capacitors C _s1 and C _s2 connected in parallel. The plurality of capacitors C _s1 and C _s2 are respectively connected to the ground via switching elements (high-frequency switching elements; control elements) 5021a (D1) and 5021b (D2) whose element state (ON / OFF) is changed by a control signal. It is connected. A switching element, which is a control element whose element state is changed by a control signal, can be configured by a PIN diode, for example, and can be switched to a conductive state or a non-conductive state according to the control signal.

An inductor Ls is further connected in parallel to the plurality of capacitors C _s1 and C _s2 connected in parallel. The inductor Ls is for dealing with a case where the output signal of the load changing unit 5001 is large. A plurality of capacitors C _s1 and C _s2 and an inductor Ls constitute a first shunt circuit body 5090. However, the inductor Ls may be omitted.

The first shunt circuit body 5090 is connected to the middle of the second transmission line 5012 in the length direction (center position in the length direction) via a line 5080 made of a microstrip line or a strip line.
The line length of the line 5080 is 3λ / 8 (λ × 3/8), and is used for converting impedance.

Four impedances Z _c1 , Z _c2 , Z _c3 , Z _{c4 of} the first shunt circuit main body 5090 corresponding to four ON / OFF combinations that the two switching elements 5021a (D1), 5021b (D2) can take. Is shown in FIG. 62 (a).
When the impedances Z _c1 , Z _c2 , Z _c3 , and Z _c4 of the first shunt circuit main body 5090 have values as shown in FIG. 62A, the first shunt circuit main body 5090 is connected to the second transmission line 5012. If a line 5080 having a line length of 3λ / 8 is provided, the impedance of the first shunt circuit 5030 viewed from the second transmission line 5012 is as shown in FIG. FIG. 62 (b) corresponds to a case where the impedance is discretely changed within the variable range of the shunt circuit impedance in FIG. 46 (a).

If only lumped constant circuit elements are used, it is difficult to generate a value with an impedance of 0 or ∞, such as Z _c1 and Z _c4 in FIG. However, since the impedance can be converted as shown in FIG. 62B by providing the line 5080 having the line length 3λ / 8, the first shunt circuit main body 5090 capable of obtaining the impedance as shown in FIG. 62B is provided. Thus, even an impedance of 0 or ∞ can be generated relatively easily.

FIG. 63 is obtained by adding a switching element (high frequency switching element; control element) 5021c (D0) to the first shunt circuit 5030 shown in FIG.
The added switching element 5021c (D0) is a control element whose element state is changed by a control signal, and can be configured by, for example, a PIN diode, and is switched to a conductive state or a non-conductive state according to the control signal. Can do.
The added switching element 5021c (D0) is provided between the second transmission line 5012 and the line 5080 having a line length of 3λ / 8.

  The switching element 5021c is turned off (non-conducting state) when the switching elements 5021a and 5021b are switched so that the first shunt circuit 5030 has the maximum impedance (maximum inductance). Thereby, the loss by the 1st shunt circuit 5030 can be suppressed. As a result, it is possible to suppress a decrease in efficiency when the output signal of the load changing unit 5001 (the output signal of the load modulation type amplification device) is large.

64 is obtained by replacing the capacitors C _s1 and C _s2 and the inductor Ls shown in FIG. 61 with lines (stubs) 5091, 5092, and 5093 made of microstrip lines or strip lines. Thereby, the loss can be reduced.
The lines 5091 and 5092 are provided as open stubs, and the line 5093 is provided as a short stub. The line length of the line 5093 is (λ / 8 + n × (λ / 2) (n is an integer of 1 or more)). By using the line 5093 as a short stub, the line length can be shortened.

In the example of the first shunt circuit 5030 described so far, the impedance of the first shunt circuit 5030 changes discretely, and thus the impedance of the load changing unit 5001 also changes discretely.
On the other hand, in FIG. 65, the impedance of the first shunt circuit 5030 continuously changes, and therefore the impedance of the load changing unit 5001 can also be continuously changed.

In FIG. 65, the first shunt circuit 5030 includes a line 5080 having a line length of 3λ / 8, and a variable capacitance element (varactor diode, LDMOS, etc.) as a control element 5021a whose element state (capacitance value) changes according to a control signal. ) 5096. The control element (control circuit) 5021a also includes a variable power supply unit 5095 that changes the voltage applied across the variable capacitance element (varactor diode) 5096 in accordance with the control signal.
The variable capacitance element 5096 changes the capacitance (capacitive reactance). However, since the line 5080 having a line length of 3λ / 8 is provided, the first shunt circuit 5030 has an impedance within the range of inductive reactance. Change.

In the first shunt circuit 5030 in which the impedance continuously changes, impedances of various values can be obtained without providing a large number of control elements, so that the circuit configuration can be simplified. In addition, fine adjustment of the impedance is facilitated.
Furthermore, even when the impedance of the first shunt circuit 5030 is desired to be inductive reactance, the first capacitance can be easily obtained by using the line 5080 having a line length of 3λ / 8 while using the readily available variable capacitance element 5096. A shunt circuit 5030 can be configured.

  66A to 66K show still other examples of the first shunt circuit 5030. FIG. 66A to 66E are examples of circuits in which the impedance is continuously changed by using a variable capacitance element as the control element 5021a whose element state is changed by a control signal. 66 (a) to 66 (e), the variable power supply unit 5095 is not shown.

  The first shunt circuit 5030 in FIGS. 66A to 66E includes an element 5081 other than the control element 5021a. In FIG. 66A, another element 5081 is an inductor (lumped constant) connected in series to the control element 5021a. In the first shunt circuit 5030 in FIG. 66 (b), the inductor (lumped constant) 5058 in FIG. 66 (a) is replaced with an inductor (distributed constant) composed of a microstrip line or a strip line.

In FIG. 66C, another element 5081 is an inductor (lumped constant) connected in parallel to the control element 5021. In the first shunt circuit 5030 in FIG. 66 (d), the inductor (concentrated multiplier) 5081 in FIG. 66 (c) is replaced with an inductor (distributed constant) composed of a microstrip line or a strip line.
In the first shunt circuit 5030 of FIG. 66 (e), a line 5080 similar to the line 5080 having a line length of 3λ / 8 shown in FIG. 61 and the like is added to the circuit shown in FIG. 66 (d).

  66F to 66K are examples of circuits in which impedance is discretely changed using a switching element (high frequency switching element; PIN diode) as the control element 5021a whose element state is changed by a control signal. .

  In the first shunt circuit 5030 of FIG. 66 (f), the variable capacitance element 5021a of FIG. 66 (e) is replaced with a switching element 5021a and a capacitor 5082. In the first shunt circuit 5030 in FIG. 66 (g), the capacitor 5058 in FIG. 66 (f) is replaced with a capacitor (distributed constant) formed of a microstrip line or a strip line.

The first shunt circuit 5030 in FIG. 66 (h) includes a plurality of switching elements 5021a and 5021b connected in parallel as control elements whose element states are changed by a control signal. In FIG. 66 (h), an inductor 5081 is connected to one switching element 5021a.
A first shunt circuit 5030 in FIG. 66 (i) is obtained by reversing the positions of the switching element 5021a and the inductor 5081 connected in series in FIG. 66 (h).

The first shunt circuit 5030 in FIG. 66 (j) is obtained by adding a capacitor 5082 between the inductor 5081 and the switching element 5021a of the first shunt circuit 5030 in FIG. 66 (i).
A first shunt circuit 5030 in FIG. 66 (k) is obtained by replacing the inductor 5081 in the first shunt circuit 5030 in FIG. 66 (h) with an inductor (distributed constant) made of a microstrip line or a strip line. In FIG. 66 (k), the inductor 5081 is an open stub.

  Also in the various circuit examples shown in FIG. 66, the value of the impedance (particularly inductive reactance) of the first shunt circuit 5030 can be changed to a desired value by appropriately setting the value of each element. Therefore, the impedance of the load changing unit 5001 can be changed to a desired value.

[7. Addendum]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
In addition, the means shown in any of the disclosed embodiments or examples can be employed in other embodiments or examples.

101: Amplifier 102: Amplifier (switching amplifier) 103: Load fluctuation unit 104: Processing unit 104a: Amplitude calculation unit 104b: Phase calculation unit 104c: Load control unit 105: Delay adjustment unit 106: Phase Modulator

201: amplification device 202: amplifier (switching amplifier), 203: load fluctuation unit, 204: processing unit, 204a: amplitude calculation unit, 204b-1, 204b-2: calculation unit, 204c: load control unit, 205: delay adjustment Part 206: Quadrature modulator

301: Amplifier, 302: Amplifier (switching amplifier), 303: Load fluctuation unit, 304: Processing unit, 304a: Amplitude calculation unit, 304c: Load control unit, 305: Delay adjustment unit, 306: Quadrature modulator

401: amplification device 402: amplifier (switching amplifier), 403: load fluctuation unit, 404: processing unit, 404a: amplitude calculation unit, 404c: load control unit, 405: delay adjustment unit, 406: quadrature modulator, 407, 408 , 409: Distortion compensation unit

501: Amplifier 502: Amplifier (switching amplifier), 503: Load fluctuation unit, 504: Processing unit, 504a: Amplitude calculation unit, 504c: Load control unit, 505: Delay adjustment unit, 506: Quadrature modulator, 508: Power supply Modulation section,

601: Amplifier 602: Amplifier (switching amplifier), 602a, 602b Amplifier (switching amplifier), 603: Load fluctuation unit, 603a, 603b: Phase adjuster, 603e: Synthesis unit, 603f: Isolator, 604: Processing unit, 604a : Amplitude calculation unit, 604c-1, 604c-2: Load control unit, 605a, 605b: Delay adjustment unit, 606: Quadrature modulator

701: amplifying devices 702a and 702b: amplifiers (switching amplifiers), 703: load changing units, 703a and 703b: phase adjusters, 703e: combining units, 703f: isolators, 704: processing units, 704a: amplitude calculating units, 704c− 1, 704c-2: load control unit, 705a, 705b: delay adjustment unit, 706: quadrature modulator, 709: distortion compensation unit

801: Amplifier 802: Amplifier (switching amplifier), 803: Load fluctuation unit, 804: Processing unit, 804a: Amplitude calculation unit, 804c-1, 804c-2: Load control unit, 805a, 805b: Delay adjustment unit, 806 : Quadrature modulator, 809: distortion compensation unit, 821, 822: variable impedance, 840: phase shifter, 843: isolator, 850: impedance converter

901: Amplifier 902: Amplifier (switching amplifier), 903: Load fluctuation unit, 904: Processing unit, 904a: Amplitude calculation unit, 904c: Load control unit, 905a, 905b, 905c, 905d: Delay adjustment unit, 906: Orthogonal Modulator, 909: distortion compensation unit, 950: impedance converter

951: Amplifier 952: Amplifier (switching amplifier), 953: Load fluctuation unit, 954: Processing unit, 9454a: Amplitude calculation unit, 954c: Load control unit, 905a, 905b, 905c: Delay adjustment unit, 956: Quadrature modulator 959: Distortion compensation unit, 960: Impedance converter

1001: Load changer (load changer)
1002: Amplifier, 1003a, 1003b: Phase adjuster, 1003c, 1003d: Impedance converter, 1003e: Synthesizer, 1003f: Isolator, 1010: Antenna, 1011: Phase controller

2001 amplifying apparatus 2002a, 2002b: amplifier, 2003e: synthesis unit, 2004: signal processing unit, 2006a, 2006b: phase modulator

3001 Load changer (load changer)
3011, 3012, 3013, 3014: Transmission line, 3021, 3022: Variable impedance, 3035: Variable capacitance diode, 3025: Inductor, 3025a: Distributed constant line, 3028: Control element (switching element), 3031: Control unit, 3040: Phaser, 3041: Phase correction unit, 3043: Isolator, P1: First port, P2: Second port, P3: Third port, P4: Fourth port

4001: Load changer (load changer)
4002: Amplifier, 4003a, 4003b: Phase adjuster, 4010: Antenna, 4111, 4112, 4113, 4114: Transmission line, 4121, 4122: Variable impedance, 4140: Phase shifter, 4141: Phase correction unit, 4150: Impedance converter 4031: Load control unit

5001: Load changer (load changer)
5001a, 5001b, 5001c, 5001d, 5001e: partial load fluctuation unit, 5002: auxiliary impedance conversion unit, 5011, 5012, 5013: transmission line, 5012a, 5012b: λ / 8 transmission line, 5021, 5021a, 5021b, 5021c: control Element (switching element; high-frequency switching element; PIN diode; variable capacitance element), 5022: additional element (inductor), 5023, resonance circuit, 5030, 5030a, 5030b, 5030c: first shunt circuit, 5031: load control unit, 5040 : Second shunt circuit, 5050: double-sided substrate, 5051: front surface, 5052: back surface, 5053, 5054: through hole, 5056: first line, 5057: second line, 5058: third line, 5061: first line, 071: first stub, 5072: second stub, 5073: the first stub, 5074: second stub, 5080: line

6001: Load changer (load changer)
6011-6015: Load section, 6021, 6021: Switch section

11: Amplifier 12: Amplifier (switching amplifier), 13: Load variation unit (load variation unit), 13a: Input unit, 13b: Load variation unit body (load variation unit body), 13c: Output unit, 13d: Control signal Input unit, 14c: Load control unit

Claims (33)

An amplifier for amplifying the signal;
A load changing unit connected to the output side of the amplifier;
An amplification device comprising:
The load fluctuation unit is
A plurality of transmission lines connected in parallel;
A first shunt circuit connected in the middle of one or more of the plurality of transmission lines connected in parallel;
With
The first shunt circuit includes a control element whose element state changes according to a control signal,
The amplifying apparatus, wherein the control element changes an impedance of the load changing unit according to a change in an element state. The amplification device is a load modulation method,
The amplification according to claim 1, further comprising a load control unit that causes an amplitude variation in an output signal of the amplifier by controlling an element state of the control element by a control signal based on an amplitude of an input signal of the amplification device. apparatus. The amplifying apparatus according to claim 1, wherein the first shunt circuit is configured such that a reactance of the first shunt circuit changes according to a change in an element state of the control element. The amplifying apparatus according to claim 3, wherein the reactance of the first shunt circuit is inductive reactance. The first shunt circuit has two or more,
The amplifying apparatus according to claim 1, wherein the first shunt circuit is provided in the middle of each of two or more transmission lines among a plurality of transmission lines connected in parallel. The amplification device according to claim 5, wherein the number of parallel connections of the transmission lines is two. A second shunt circuit which includes an element whose element state does not change but does not include the control element;
The second shunt circuit is provided in the middle of one or more transmission lines other than the transmission line provided with the first shunt circuit among a plurality of transmission lines connected in parallel. The amplification device according to claim 1. The amplifying apparatus according to claim 7, wherein reactance of the second shunt circuit is inductive reactance. The amplifying apparatus according to claim 1, wherein the control element discretely changes an impedance of the load changing unit. The amplifying apparatus according to claim 1, wherein the control element is a switching element that switches between a conductive state and a non-conductive state according to a control signal. The amplification device according to claim 10, further comprising an additional element that forms a resonance circuit together with the switching element. The amplification device according to claim 10 or 11, wherein the first shunt circuit includes a plurality of the switching elements. The amplification device according to claim 1, wherein the control element is a high-frequency switching element. The amplifying apparatus according to claim 1, wherein the control element is a PIN diode. The amplifying apparatus according to claim 1, wherein the control element is connected between a midway position of the transmission line and a ground. The amplifying apparatus according to any one of claims 1 to 15, wherein the control element is connected in series so as to be interposed in a midway position of the transmission line. The amplification device according to claim 1, wherein the transmission line is a λ / 4 transmission line (λ is a signal wavelength). The amplification device according to claim 17, wherein the control element is connected to a position where a line length from an end of the λ / 4 transmission line to which the control element is connected is λ / 8. The amplifying apparatus according to claim 1, wherein the control element continuously changes the impedance of the load changing unit. Each of the plurality of transmission lines connected in parallel is a λ / 4 transmission line (λ is a signal wavelength),
The amplifying apparatus according to any one of claims 1 to 19, wherein an overall characteristic impedance of a plurality of transmission lines connected in parallel is a value that does not match impedance to a circuit to which a signal output from the load changing unit is applied. . 21. The amplifying apparatus according to claim 20, wherein an overall characteristic impedance of the plurality of transmission lines connected in parallel is smaller than a characteristic impedance of a circuit to which a signal output from the load changing unit is given. The amplification according to any one of claims 1 to 16, 18, and 19, wherein each of the plurality of transmission lines connected in parallel is set to a line length other than λ / 4 (λ is a signal wavelength). apparatus. The first shunt circuit is
A switching element as the control element;
When the switching element is in a conductive state, it becomes an open stub having a line length of (λ / 2) × n (λ is a signal wavelength; n is an integer of 1 or more),
2. When the switching element is in a non-conducting state, the switching element is configured to be a stub having a predetermined line length (hereinafter referred to as “non-conducting state line length”) for changing the impedance of the load changing unit. The amplification device according to any one of ˜22. The non-conductive state line length is taken as D _L,
The first shunt circuit is
Is connected to the middle of the connection position of the parallel-connected plurality of transmission lines, a first stub consisting line line length is D _L,
A s / 4 line length second stub connected to the first stub via the switching element,
The amplifying apparatus according to claim 23, wherein the second stub is connected to a position λ / 4 from the connection position in the first stub via the switching element. The non-conductive state line length is taken as D _L,
The first shunt circuit is
A first stub formed of a line having a line length L, connected to a connection position in the middle of a plurality of transmission lines connected in parallel;
The amplifying apparatus according to claim 23, further comprising a second stub having a length of ((λ / 2) -L) connected in series to the first stub through the switching element. The non-conductive state line length is taken as D _L,
λ / 8 ≦ D _L ≦ 3λ / 8
The amplification device according to any one of claims 23 to 25. An auxiliary impedance converter provided between the amplifier and the load changing unit;
27. The auxiliary impedance conversion unit performs impedance conversion so that the impedance of the load variation unit viewed from the amplifier varies in a range higher than an impedance matching impedance with the amplifier. The amplifying device described. The amplification device according to any one of claims 1 to 27, wherein the load changing unit includes a plurality of partial load changing units including a plurality of transmission lines connected in parallel. The amplification device according to any one of claims 1 to 28, wherein the plurality of partial load fluctuation units are cascade-connected in series. 30. The plurality of partial load fluctuation portions are provided so that the respective partial load fluctuation portions are alternately positioned on the front surface and the back surface of the double-sided board on which circuit patterns are formed on both the front and back surfaces. Amplification equipment. The amplification device according to any one of Claims 1 to 30, wherein the load changing unit further includes an isolator that allows signals output from the plurality of transmission lines connected in parallel to pass therethrough.   A wireless communication device comprising the amplifying device according to claim 1, wherein the amplifying device amplifies a communication signal. A plurality of transmission lines connected in parallel;
A first shunt circuit connected in the middle of one or more of the plurality of transmission lines connected in parallel;
With
The first shunt circuit includes a control element whose element state changes according to a control signal,
The load variator, wherein the control element changes an impedance of the load variator according to a change in an element state.

Images