JP2003318750A - Radio transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio transmitter to be controlled for a specified value of radio transmission power, which feeds an antenna with an original transmission power outputted from a transmission system amplifier circuit, without attenuating the power, thereby greatly improving the circuit efficiency. <P>SOLUTION: An output signal from an orthogonal modulator 7 is inputted to a transmission system amplifier circuit 8, to feed a coupling circuit 9 with its amplified transmission output signal d. The signal d is branched by the coupling circuit 9 into an antenna feed signal e fed to an antenna 10 and a power level detecting signal f fed to a detector circuit 11. The antenna feed signal e, outputted to the antenna 10, is the fundamental wave of the output signal d, as it is. The power level detecting signal f is a signal of extracted harmonic components only. The detector circuit 11 generates a detection voltage V1, which is then inputted to a base band circuit 12 for controlling a loop, to hold the transmission power constant. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless transmitter which controls wireless transmission power to a predetermined value.

[0002]

2. Description of the Related Art A radio transmitting apparatus for controlling a transmission power to a predetermined value has mainly two types of radio transmitting apparatus having a function of matching the transmission power to a predetermined value.
The wireless transmission device maintains its own transmission power at a predetermined value by itself, and the second mode receives the transmission power designation data transmitted from another wireless station, and determines the transmission power of itself based on the data. It keeps a predetermined value.

The radio transmitting apparatus for mobile communication performed between the base station and the mobile station is the case of the radio transmitting apparatus of the above-mentioned second aspect, and is on the radio wave propagation path between the base station and the mobile station. Is in an environmental state where the space changes constantly due to buildings and terrain existing along the route, as well as the distance between the two, and even if the mobile station transmits with a constant output, the received power level on the base station side Always changes.

In order to maintain a constant communication quality, the transmission power of the mobile station moves based on an instruction from the base station side so that the reception power level of the mobile station received by the base station is always constant. The transmission power must be adjusted on the station side, and the mobile station detects the transmission power level by itself, and reaches the transmission power level requested by the base station (mobile station).
You must always monitor whether the outputs of are matched.

A radio transmitting apparatus for this purpose is constructed as shown in FIG. 10. A signal obtained by modulating an I / Q signal into a carrier wave by a quadrature modulator 1 is inputted to a transmitting system amplifying circuit 2 and, if necessary, a filter. The transmission signal a output from the transmission system amplification circuit 2 is supplied to the coupling circuit 3 by suppressing unnecessary spurious signals or by being input by the amplification circuit section while being amplified.

The transmission output signal a is branched by the coupling circuit 3 into an antenna supply signal b and a power level detection signal c, and the antenna supply signal b is supplied to the antenna 4.
The power level detection signal c is input to the detection circuit 5.

This transmission output signal a is a signal containing a transmission signal fundamental wave and a transmission signal harmonic as shown in FIG. 11, and its transmission output value has a value P1. When such a transmission output signal a is input to the coupling circuit 3 and branched into the antenna supply signal b and the power level detection signal c, as shown in FIG. 11, a predetermined transmission output value P1 is obtained. The antenna supply signal b having a value P2 (see FIG. 12) whose output is reduced by the amount of attenuation ΔP due to the coupling loss (branch loss) is supplied to the antenna 4.

The power level detection signal c branched by the coupling circuit 3 is supplied to the detection circuit 55, and the detection voltage V converted into a voltage signal by the detection circuit 5 is obtained.

Utilizing the fact that the voltage value of the detection voltage V corresponds to the transmission power from the antenna 4 in a one-to-one relationship, the transmission power level is calculated from the detection voltage V and set in the baseband circuit 6. Reference voltage, that is, the transmission power control signal by comparing the set value based on the transmission power designation data obtained by receiving the radio wave transmitted from a radio transmission station other than the radio transmission device, and judging the magnitude. A power control method called so-called loop control in which C is output to the transmission system amplifier circuit 2 and fed back to the transmission power control system is generally performed. As long as such a loop control method is adopted in the wireless transmission device, it is necessary to branch a part of the transmission output.

The coupling degree and the passage loss by the coupling circuit 3 are in a trade-off relationship, but the coupling degree is set in accordance with the characteristic of the detection circuit 5, and the transmission characteristics of the transmission output signal a and the antenna supply signal b are set. For example, as shown in FIG. 13, the transmission output signal a and the power level detection signal c have a value Q2 which is lower than the reference value Q1 in the ideal state by a passage loss ΔQ.
14 has a value of R2 which is lowered by the coupling degree ΔR as shown in FIG. 14, and the coupling degree is generally set in accordance with the characteristic of the detection circuit 5, but the frequency characteristic is particularly positive. I don't give it to anyone.

On the other hand, in the case of the above-described wireless transmission device of the first aspect in which the wireless transmission device alone maintains its own transmission power at a predetermined value, the transmission output of the wireless transmission device is calculated as "power supply voltage fluctuation, temperature fluctuation, various The transmission output signal is branched into an antenna supply signal and a power level detection signal by a coupling circuit so that a predetermined value can be obtained even if "characteristic fluctuation of electronic parts" occurs, and the transmission output is looped based on the power level detection signal. Control is taking place.

[0012]

A conventional radio transmitter inputs a transmission output to a coupling circuit, branches it into an antenna supply signal and a power level detection signal, and supplies the branched antenna supply signal to an antenna. Since the target transmission power is obtained by detecting the power level detection signal and performing loop control of the transmission output based on the result, the original transmission output from the transmission system amplifier circuit The drawback is that the power is attenuated due to the coupling loss by the coupling circuit.

For this reason, the amplification factor must be increased in order to compensate for the attenuation, and there is a problem that the circuit efficiency is reduced accordingly.

If the loss due to such a coupling circuit is compensated by increasing the gain of the transmission system amplifying circuit, the current consumption of the circuit increases significantly, and when the wireless transmission device is a mobile phone, the talk time by the power supply battery can be increased. Is greatly reduced.

For example, assuming that the output of the final stage amplifier of the transmission system amplifier circuit is 30 dBm (1 W) and the loss due to the coupling circuit is 0.5 dB, it is attempted to maintain a predetermined antenna radiation power, 30.5d for output of amplifier
B (1.12 W) is required. Therefore, if the efficiency of the amplifiers is the same, the current consumption increases by about 12%.

This means that, for example, if the current consumption of the mobile phone is 600 mA, an increase in current consumption of 70 mA or more must be expected to compensate for the loss of the coupling circuit. Is reduced to about 10 to 15 minutes in terms of call time, which is a big problem.

Therefore, an object of the present invention is to provide a wireless transmission device in which the wireless transmission power is controlled so as to have a predetermined value,
It is an object of the present invention to provide a wireless transmission device capable of supplying an original transmission output from a transmission system amplifier circuit to an antenna without attenuating it and significantly improving circuit efficiency.

[0018]

In order to solve the above-mentioned problems, the radio transmitting apparatus according to the present invention adopts the characteristic configuration as described below.

(1) In a wireless transmission device in which the wireless transmission output is controlled to have a predetermined value, extraction means for extracting a harmonic component contained in the wireless transmission signal and the level of the signal extracted by the extraction means are set. And a transmission power control means for controlling the wireless transmission output so that the level value detected by the detection means matches a set value having a certain correlation with the predetermined value. Wireless transmitter.

(2) A radio transmitting apparatus in which the (1) extracting means or the detecting means includes a circuit for amplifying a harmonic component contained in the transmission signal.

(3) The extraction means of the above (1) is a radio transmission configured to extract the harmonic component from the transmission signal by a circuit formed by a capacitor and a coil or a self-resonant circuit formed by a capacitor. apparatus.

(4) A radio transmitting apparatus in which any one of the predetermined values (1) to (3) is set to a predetermined value.

(5) A radio transmitting apparatus in which any one of the predetermined values (1) to (3) is set to a value based on power control command data transmitted from another radio station.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. First, a first embodiment will be described with reference to FIGS. 1 to 6. In addition,
The present embodiment applies the present invention to a mobile station that wirelessly communicates with a base station, receives transmission power designation data transmitted from another wireless station, and determines its own transmission power based on the data. The present invention is applied to a wireless transmission device that maintains a value.

As shown in FIG. 1, in the radio transmitter, a signal obtained by modulating an I / Q signal into a carrier wave by a quadrature modulator 7 is input to a transmission system amplifier circuit 8, and an unnecessary spurious signal is filtered by a filter if necessary. A transmission output signal d, which is input while being suppressed or amplified by the amplification circuit section and output from the transmission system amplification circuit 8, is supplied to the coupling circuit 9.

The transmission output signal d is branched by the coupling circuit 9 into the antenna supply signal e and the power level detection signal f, the antenna supply signal e is supplied to the antenna 10, and the power level detection signal f is detected by the detection circuit. 11 is input.

The transmission output signal d is a signal including a transmission signal fundamental wave and a transmission signal harmonic as shown in FIG.
The transmission output value of the fundamental wave has a value of P1, and the transmission output value of the harmonic wave has a value of P3. Such a transmission output signal d is input to the coupling circuit 9, and the harmonic component is extracted while the fundamental wave component remains unchanged.

Therefore, the antenna supply signal e is shown in FIG.
As shown in (4), the component of the transmission signal fundamental wave remains as it is, and the harmonic component becomes the value P4 which is lower than the value P3 in the transmission output signal d by the attenuation Δ34.

The coupling degree and the passage loss by the coupling circuit 9 have a predetermined correlation, but the coupling degree is set in accordance with the characteristic of the detection circuit 11, and the transmission characteristics of the transmission output signal d and the antenna supply signal e are For example, as shown in FIG. 4, as compared with the reference value S1 in the ideal state, the fundamental component remains as it is and the harmonic component has a value reduced by the passage loss ΔS1.
The transfer characteristics of the power level detection signal f and the power level detection signal f have a value that is reduced by the coupling degree ΔS2 as shown in FIG. 5, and the frequency characteristic of the detection circuit 11, that is, the characteristic of extracting the harmonic component, The harmonic component is extracted while the component remains unchanged.

As for the relationship between the power levels of the transmission signal fundamental wave and the harmonic wave, as shown in FIG. 6, the fundamental wave has a value P5 which is attenuated by ΔP15 from the reference value P1, and the harmonic wave is greater than the reference value P3. It has a value of P6 attenuated by ΔP36. As described above, although the harmonic has an absolute power level different from that of the fundamental wave, the harmonic wave changes according to the power level of the fundamental wave, so that there is no problem in controlling the power of the transmission signal by the harmonic detection voltage.

By utilizing the fact that the voltage value of the detection signal V1 output from the detection circuit 11 has a one-to-one correspondence with the transmission power from the antenna 10, the transmission power level is calculated from this detection voltage V1. , A reference voltage set in the baseband circuit 12, that is, a set value based on transmission power designation data obtained by receiving a radio wave transmitted from a radio transmission station different from the radio transmission device, The transmission power control signal C1 is output to the transmission system amplifier circuit 8 by judging the magnitude, and loop control is performed by feeding back to the transmission power control system to control the transmission radio wave output from the antenna 10 to match the set value. To be done.

A concrete configuration example of the coupling circuit 9 described so far is constituted by a circuit in which a capacitance component by the capacitor 13a and an inductance component by the coil 13b are connected in series as shown by reference numeral 13 in FIG. Transmission output signal d output from the system amplifier circuit 8
Is supplied to the antenna 10 as the antenna supply signal e in which the fundamental wave component remains unchanged by the coupling circuit 13.
Only the harmonic component of the transmission output signal d is extracted and output to the detection circuit 11 as the power level detection signal f.

As another example of the coupling circuit 13, FIG.
As shown by reference numeral 14, the transmission output signal d output from the transmission system amplifying circuit 8 by the self-resonant circuit formed of the capacitance component by the capacitor 14a alone has the fundamental wave component by the coupling circuit 13. The antenna supply signal e in that state is supplied to the antenna 10, and only the harmonic component of the transmission output signal d is extracted and output to the detection circuit 11 as a power level detection signal f.

Next, another embodiment of the present invention will be described with reference to FIG. In this embodiment, a high frequency amplifier circuit 15 for amplifying the power level detection signal f output from the coupling circuit 9 in the above-described embodiment is inserted, and the output signal g is input to the detection circuit 11. Thus, it is effective when the transmission output signal d output from the transmission system amplifier circuit 8 contains a small number of harmonic components.

The configuration and operation of the preferred embodiment of the wireless transmission device according to the present invention have been described above in detail. However, such an embodiment is merely an example of the present invention and does not limit the present invention in any way. Those skilled in the art can easily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention.

For example, the wireless transmission devices according to the two modes described so far are examples in which their transmission powers are controlled based on a command from the base station, but the present invention is not limited to this, and the present invention is not limited to this. Even in the wireless transmission device that controls the device so that the transmission power is set to a value fixedly fixed in advance, the fundamental wave of the transmission signal component output from the transmission system amplification circuit is output in the same manner as in the above-described embodiment. It goes without saying that the antenna can be supplied without level attenuation.

Further, the example of inserting the high frequency amplifier circuit for amplifying the power level detection signal is not limited to the case of connecting between the coupling circuit and the detection circuit, but is configured to be included in the coupling circuit itself. Alternatively, the detection circuit may be included in the detection circuit itself.

Therefore, the radio transmitting apparatus according to the present embodiment, when the transmission output signal is branched into the antenna supply signal and the power level detection signal, uses the "fundamental wave component" as the antenna supply signal and the "harmonic component". Is used as the power level detection signal, it is possible to perform efficient circuit operation without the original transmission power output from the transmission system amplifier circuit being attenuated due to coupling loss.

Further, since the amount of attenuation for coupling is negligibly small, it is not necessary to increase the amplification factor of the circuit,
The total power consumption can be reduced as compared with the conventional one.

In this embodiment, since the harmonic component contained in the transmission signal is positively utilized, it serves as a "notch filter circuit for attenuating the harmonic component" as seen in the conventional circuit. Therefore, the circuit can be omitted, the circuit configuration can be simplified, and the power amplifier having a high harmonic level can be used as it is, so that the versatility of the circuit can be improved.

[0041]

As is apparent from the above description, the radio transmitting apparatus according to the present invention is a radio transmitting apparatus in which the radio transmitting power is controlled so as to have a predetermined value. It is possible to provide a wireless transmission device capable of supplying a transmission output to an antenna without attenuating it and significantly improving circuit efficiency.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a main part of a wireless transmission device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram for explaining components included in the transmission signal shown in FIG.

FIG. 3 is a characteristic diagram for explaining components included in the antenna supply signal shown in FIG.

FIG. 4 is a characteristic diagram for explaining a transfer characteristic of a combination of the transmission output signal and the antenna supply signal shown in FIG.

5 is a characteristic diagram for explaining a transfer characteristic of coupling of the transmission output signal and the power level detection signal shown in FIG. 1. FIG.

FIG. 6 is a characteristic diagram for explaining the relationship between the power levels of the fundamental wave and the harmonic wave of the coupling between the transmission output signal and the power level detection signal shown in FIG.

FIG. 7 is a circuit block diagram for explaining a specific example of a coupling circuit used in the wireless transmission output control device according to the present invention.

FIG. 8 is a circuit block diagram for explaining another specific example of the coupling circuit used in the wireless transmission output control device according to the present invention.

FIG. 9 is a circuit block diagram showing a main part of a wireless transmission device according to another embodiment of the present invention.

FIG. 10 is a circuit block diagram showing an example of a conventional wireless transmission device.

FIG. 11 is a characteristic diagram for explaining components included in the transmission signal shown in FIG.

FIG. 12 is a characteristic diagram for explaining components included in the antenna supply signal shown in FIG. 1.

13 is a characteristic diagram for explaining the transfer characteristic of the coupling between the transmission output signal and the antenna supply signal shown in FIG.

14 is a characteristic diagram for explaining a transfer characteristic of coupling of the transmission output signal and the power level detection signal shown in FIG.

[Explanation of symbols]

1,7 Quadrature modulator 2,8 Transmission system amplifier circuit 3,9,13,14 coupling circuit 4,10 antenna 5,11 Detection circuit 6,12 baseband circuit 13a, 14a capacitors 13b coil 15 High frequency amplifier circuit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5K004 AA05 AA08 FF00 JF00                 5K060 BB07 CC04 CC11 CC12 DD04                       HH06 HH13 JJ03 JJ04 JJ17                       KK04 LL01 LL15 LL25                 5K067 AA42 BB04 BB21 DD27 DD42                       EE02 EE10 GG08 GG09

Claims (5)

[Claims] 1. A wireless transmission device in which wireless transmission power is controlled so as to have a predetermined value. Extraction means for extracting a harmonic component included in a wireless transmission signal; and level of a signal extracted by the extraction means are detected. And a transmission power control means for controlling the wireless transmission output so that the level value detected by the detection means matches a set value having a certain correlation with the predetermined value. A wireless transmission device. 2. The radio transmitting apparatus according to claim 1, wherein the extracting means or the detecting means includes a circuit that amplifies a harmonic component included in the transmission signal. 3. The extracting means is configured to extract the harmonic component from the transmission signal by a circuit formed by a capacitor and a coil or a self-resonant circuit formed by a capacitor. 1. The wireless transmission device according to 1. 4. The wireless transmission device according to claim 1, wherein the predetermined value is set to a predetermined value. 5. The wireless transmission device according to claim 1, wherein the predetermined value is set to a value based on power control command data transmitted from another wireless station. .