JP5822784B2 - Power amplification device and power amplification method - Google Patents

Description

  The present invention relates to a power amplification device and a power amplification method including a plurality of power amplifiers, and more particularly to a power amplification device and a power amplification method for an array antenna.

  As an active antenna in which an antenna element and an amplifier are integrated, the technique of Non-Patent Document 1 is known. In general, a communication device includes an antenna and a transmitter / receiver separately, and the antenna and the transmitter / receiver are connected by an RF cable. With the progress of radar technology, array antennas in which a large number of antenna elements are periodically arranged have been put into practical use. The antenna elements constituting the array antenna are tournament-synthesized by a power combiner and connected to the transceiver by an RF cable. When the beam formed by the array antenna is directed to a large number of targets, the phase of the signal fed to the antenna element is controlled. In this configuration, the antenna and the transmitter / receiver are separate devices and are not integrally configured. An active antenna is a circuit in which an antenna and a power amplifier are integrated, and has an advantage that an interstage matching circuit between the antenna and the power amplifier can be made unnecessary and can be integrated.

  Further, as a power amplifying apparatus that is not an active antenna but has a plurality of power amplifiers and realizes input / output characteristics and delay characteristics of each power amplifier with high accuracy, there is a multi-port amplifying apparatus to which a feedforward configuration is applied ( Patent Document 1, Patent Document 2). With this power amplification device, the input / output characteristics and delay characteristics of the plurality of power amplifiers can be easily made uniform.

JP-A-9-135124 International Publication No. 2001/022574

K. Chang, R. A. York, P. S. hall, and T. Itoh, “Active integrated antennas,” IEEE Transactions on Microwave Theory and Technique, vol. 50, no. 3, pp. 937-644, March 2002.

  In an active antenna such as Non-Patent Document 1, a high-efficiency broadband amplifier using radar technology is used from the viewpoint of securing a necessary operating bandwidth and reducing power consumption. Therefore, in order to operate the beam width and beam direction control as designed, it is necessary to ensure the input / output characteristics and delay characteristics of a plurality of high-efficiency broadband amplifiers within a predetermined range. In order to satisfy this requirement, an adjustment circuit that performs circuit adjustment at the manufacturing stage and finely adjusts the amplitude and phase of the active antenna input signal is provided. Thus, there is a problem that it is difficult to control the beam width and beam direction with high accuracy.

  On the other hand, the power amplifying devices of Patent Documents 1 and 2 have a problem that efficiency is poor. The techniques of Patent Documents 1 and 2 are feedforward amplifiers, which use two power amplifiers (a main amplifier and an auxiliary amplifier). Reference 1 (Y. Suzuki, S. Narahashi, and T. Nojima, “Highly efficient feed-forward amplifier using a harmonic reaction amplifier,” in IEEE Radio and Wireless Symposium 2009, WE1A-5, Jan. 2009.) As can be seen from Document 2 (Japanese Patent Laid-Open No. 2009-200688), the efficiency of the Feedford amplifier based on the power amplifier for the base station corresponding to the third generation mobile phone system is about 20% even if the efficiency is increased. is there. Therefore, when the power amplification devices of Patent Documents 1 and 2 are applied to an active antenna, there is a problem that efficiency is low.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to make the characteristics of each power amplifier uniform and increase the efficiency in a power amplifying apparatus including a plurality of power amplifiers.

  The power amplification device of the present invention has a plurality of power amplifiers. Each power amplifier of the power amplification device of the present invention includes a first path, a second path, a distribution unit, a directional coupling unit, and a control unit. The first path includes a variable attenuation unit, a variable phase unit, and an amplification unit. The second route has a predetermined range of characteristics. The characteristic in the predetermined range means, for example, a range in which the attenuation characteristic and delay characteristic for each frequency are predetermined. The distribution unit divides the input signal into two, and distributes one to the first path and the other to the second path. The directional coupling unit generates a combined signal by combining a part of the output of the first path with the output of the second path. The remainder of the output of the first path becomes the output of the power amplifier. The control unit controls the variable attenuation unit and the variable phase unit so that the combined signal becomes small.

  According to the power amplifying device of the present invention, all the power amplifiers are provided with the second path having characteristics in a predetermined range. Therefore, the signals that have passed through the second path are substantially equal in all the power amplifiers. In addition, each power amplifier controls the variable attenuation unit and the variable phase unit of the first path with reference to the signal that has passed through the second path. Therefore, the characteristics (for example, amplification characteristics, delay characteristics, etc.) of each power amplifier can be made uniform. In addition, since an amplifier is not required in the second path and the degree of coupling of the directional coupling unit can be freely adjusted in a wide range, the efficiency of the power amplification device can be increased.

1 is a diagram illustrating a functional configuration example of a power amplification device according to a first embodiment. The figure which shows the structural example of a power amplifier. The figure which shows drain efficiency calculation results. The figure which shows the function structural example of the power amplification apparatus of a modification.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

  FIG. 1 shows an example of a functional configuration of the power amplification device according to the first embodiment, and FIG. 2 shows an example of the configuration of the power amplifier. The power amplifying apparatus 10 includes N (N is an integer of 2 or more) power amplifiers 100-1,. The power amplifying apparatus 10 may also include a common control unit 180. The power amplifier 100-n (n is an integer of 1 to N) includes a first path 110-n, a second path 120-n, a distribution unit 130-n, a directional coupling unit 140-n, and a control unit 150-n. , Input signal terminals 191-n and output signal terminals 192-n.

  The first path 110-n includes a variable attenuation unit 111-n, a variable phase unit 112-n, and an amplification unit 113-n. The second path 120-n has a predetermined range of characteristics. The characteristic in the predetermined range means, for example, a range in which the attenuation characteristic and delay characteristic for each frequency are predetermined. As a specific example of the second path, a delay line 121-n as shown in FIG. 2 may be used, or a delay equalizer using a delay filter or the like may be used. In order to control the beam width and beam direction of an array antenna (not shown) with high accuracy using the power amplifier 10, the frequency characteristics and linearity of the amplification factors of the power amplifiers 100-1,. These characteristics of the power amplifiers 100-1,..., N are more uniform. In other words, even if the frequency characteristics and linearity of the individual power amplifiers 100-1,..., N are good, if the individual difference is large, the beam width and beam direction of the array antenna can be controlled with high accuracy. Can not. Therefore, either the delay line 121-n or the delay equalizer may be used as the second path 120-n, but all the second paths 120-1,..., N satisfy the characteristics in a predetermined range. It is important that The range may be determined as appropriate from the accuracy required for the beam width and beam direction control of the array antenna.

  The distribution unit 130-n divides the input signal input from the terminal 191-n into two, and distributes one to the first path 110-n and the other to the second path 120-n. The distribution unit 130-n may be configured by a coupler 131-n, for example. The directional coupler 140-n combines a part of the output of the first path 110-n with the output of the second path 120-n to generate a combined signal. The directional coupler 140-n may be configured with a directional coupler 141-n, for example. The remaining output of the first path becomes the output of the power amplifier and is output from the terminal 192-n. The control unit 150-n controls the variable attenuation unit 111-n and the variable phase unit 112-n so that the combined signal becomes small. The distribution ratio in the distribution unit 130-n and how much of the output of the first path to be combined with the output of the second path in the directional coupling unit 140-n depends on the power gain of the amplification unit 113-n, which will be described later. The drain efficiency may be determined in consideration of the drain efficiency.

  If the common control unit 180 is also provided, the common control unit 180 monitors the intensity of the combined signal of all the power amplifiers 100-1,. Specifically, information on the intensity of the composite signal is collected from all the control units 150-1,. A failure can be found by monitoring whether there is a power amplifier 100-n whose combined signal intensity is not controlled within a predetermined range. Furthermore, if the setting information of the variable attenuation unit 111-n and variable phase unit 112-n is collected from the control units 150-1,..., N, the control unit whose intensity of the combined signal cannot be controlled within a predetermined range. It is also possible to instruct 150-n to perform control using setting information of another control unit.

  As described above, since the control unit 150-n controls the variable attenuation unit 111-n and the variable phase unit 112-n so that the composite signal becomes small, the control unit 150-n passes through the first path 110-n and is a directional coupling unit. The signal extracted and synthesized at 140-n and the signal that has passed through the second path 120-n are controlled to have equal amplitude and opposite phase. That is, if the characteristics of all the second paths 120-1,..., N are uniform (characteristics in a predetermined range), the characteristics (for example, amplification characteristics, delay characteristics, etc.) of the power amplifiers 100-1,. ) Can be made uniform.

Next, the efficiency of the power amplifier 100-n will be examined. The features of the configuration of the power amplifier 100-n are that there is no linear amplifier in the delay line like the auxiliary amplifier of the feedforward amplifier, and that the loss of the output side circuit of the amplifier 113-n is minimized. If the output power of the amplifying unit 113-n is P _O , the supply power of the individual amplifier is P _DC , and the coupling amount of the directional coupler is C ₂ , the drain efficiency η of the basic configuration of the power amplifier is

It becomes. From this equation, the drain efficiency of the power amplifier 100-n is determined by the degree of coupling of the directional coupler 140-n. Note that the power consumption in the variable attenuator 111-n and the variable phase unit 112-n is generally small, and thus is not considered in the above formula. FIG. 3 shows the drain efficiency calculation result of the above formula. The horizontal axis represents the coupling factor C ₂ , and the vertical axis represents the drain efficiency η. The maximum drain efficiency of the amplifying unit 113-n was set to 50%, 75%, and 80%. In either case, the degree of coupling C ₂ is if more than 20 dB, value close to the maximum drain efficiency is expected to be obtained. Since the degree of coupling of the directional coupling unit 140-n can be freely adjusted in a wide range, the degree of coupling can be set to 20 dB or more, and the influence on the drain efficiency of the power amplifier 100-n can be reduced. Moreover, since an amplifier is not required for the second path, the efficiency of the power amplifying apparatus 10 can be increased.

[Modification]
FIG. 4 shows a functional configuration of the modified example. The power amplifying device 20 is different from the power amplifying device 10 of the first embodiment in that each power amplifier 200-n includes a pilot signal supply unit 260-n, and the processing of the control unit 250-n and the common control unit 280. Others are the same as the power amplifying apparatus 10. The common control unit 280 may not be provided.

  The pilot signal supply unit 260-n inputs a pilot signal having a predetermined frequency component and intensity to the input side of the distribution unit 130-n. Accordingly, the pilot signal passes through the first path 110-n and the second path 120-n while being combined with the input signal input from the terminal 191-n, and is combined by the directional coupling unit 140-n. It is input to the controller 250-n. Therefore, the composite signal includes a component of a pilot signal. The control unit 250-n controls the variable attenuation unit 111-n and the variable phase unit 112-n so that the component of the pilot signal in the combined signal becomes small.

  In the case of the power amplifying apparatus 10 of the first embodiment, the signal to be controlled is an input signal (the signal itself to be amplified). In this case, since the input signal (the signal itself to be amplified) is different for each power amplifier 100-n, the uniformity of the power amplifier may be reduced due to the nonuniformity of the signal to be controlled. In the case of a method using a pilot signal, the signal to be controlled can be made the same at the input portion, so that the uniformity of the power amplifier can be further improved. It should be noted that if one frequency (narrow band signal) is selected from the frequency bands not used for communication as the pilot signal, the intensity of the component of the pilot signal in the synthesized signal can be easily controlled. However, even if a frequency band having a bandwidth is selected, the signal to be controlled can be made the same at the input portion, so that the effect of improving uniformity can be obtained. Further, the predetermined frequency component and intensity may be appropriately determined from the uniformity condition required for the power amplification device.

  When the common control unit 280 is provided, the common control unit 280 monitors the intensity of the component of the pilot signal in the combined signal of all the power amplifiers 200-1,. Specifically, information on the intensity of the component of the pilot signal in the combined signal is collected from all the control units 250-1,. A failure can be found by monitoring whether there is a power amplifier 200-n whose intensity is not controlled within a predetermined range. Furthermore, if the setting information of the variable attenuation unit 111-n and variable phase unit 112-n is also collected from the control units 250-1,..., N, the intensity of the component of the pilot signal in the combined signal is within a predetermined range. It is also possible to instruct the control unit 250-n that has not been controlled to perform control using the setting information of another control unit.

10, 20 Power amplifier 100, 200 Power amplifier 110 First path 111 Variable attenuating section 112 Variable phase section 113 Amplifying section 120 Second path 121 Delay line 130 Distribution section 131 Coupler 140 Directional coupling section 141 Directional coupler 150, 250 Control unit 180, 280 Common control unit 191, 192 Terminal 260 Pilot signal supply unit

Claims (7)

A power amplifying device having a plurality of power amplifiers,
Each of the power amplifiers is
A first path having a variable attenuation section, a variable phase section, and an amplification section;
A second path having a predetermined range of characteristics;
A distribution unit that divides an input signal into two and distributes one to the first path and the other to the second path;
A directional coupling unit configured to combine a part of the output of the first path with the output of the second path to generate a combined signal;
A control unit that controls the variable attenuation unit and the variable phase unit so that the combined signal is small ;
Other than the part of the output of the first path is set as the output of the power amplifier.
Power amplifier you wherein a. The power amplification device according to claim 1,
A power amplifying apparatus comprising a common control unit that monitors the intensity of the combined signal of all the power amplifiers. The power amplification device according to claim 1,
A pilot signal supply unit that inputs a pilot signal having a predetermined frequency component to the input side of the distribution unit is also provided,
The control unit controls the variable attenuation unit and the variable phase unit so that a component of a pilot signal in the combined signal becomes small. The power amplifying device according to claim 3,
A power amplifying apparatus comprising a common control unit that monitors the intensity of a component of a pilot signal in the combined signal of all the power amplifiers. The power amplifying device according to any one of claims 1 to 4,
The second path is composed of a delay line ,
The characteristic of the predetermined range is determined from the accuracy required for the beam width and beam direction control of the array antenna that receives the output of the power amplifier. The power amplifying device according to any one of claims 1 to 4,
The second path have a delay equalizer,
The characteristic of the predetermined range is determined from the accuracy required for the beam width and beam direction control of the array antenna that receives the output of the power amplifier. A power amplification method using a plurality of power amplifiers,
Each of the power amplifiers is
A first path having a variable attenuation section, a variable phase section, and an amplification section;
A second path having a predetermined range of characteristics;
A distribution unit that divides an input signal into two and distributes one to the first path and the other to the second path;
A directional coupling unit configured to combine a part of the output of the first path with the output of the second path to generate a combined signal;
In all the power amplifiers, the variable attenuation unit and the variable phase unit are controlled so that the combined signal becomes small ,
Other than the part of the output of the first path is set as the output of the power amplifier.
A power amplification method characterized by the above.

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