JP2012129870A - Feed-forward distortion compensation high frequency amplification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a feed-forward distortion compensation high frequency amplification device that can implement a reduced loss when applied to amplify a wideband signal having a plurality of passbands, such as a multi-carrier signal.SOLUTION: A BPF 301 is connected to a main output of a second A-band directional coupler 120, and a BPF 302 is connected to a main output of a second B-band directional coupler 220. A combiner 30 combines outputs of the BPF 301 and BPF 302 to interconnect a main line of an A-band distortion compensation loop and a main line of a B-band distortion compensation loop before supplying them to an AB-shared directional coupler 133 via a delay line 305, and an AB-band-shared signal output terminal 150 outputs an A-band signal and a B-band signal.

Description

  The present invention relates to a feedforward type amplifying apparatus having a compensation loop in an amplifying system, and more particularly to a feedforward distortion compensating high frequency amplifying apparatus suitable for amplifying a multicarrier signal having a wide frequency band.

In mobile communication base station apparatuses and relay station apparatuses, a so-called multicarrier signal, which is a signal composed of a number of carrier waves arranged at predetermined frequency intervals and appropriately modulated, is used for radio frequency amplification. Sending.
Therefore, when the multicarrier signal is processed, if the linearity of the amplifier used for high frequency amplification is insufficient, various distortions such as intermodulation distortion occur.
This distortion becomes an obstacle to realizing normal and high-quality communication. Therefore, an amplifier used for amplification of a multicarrier signal is required to have good linearity over the entire frequency band to which the multicarrier signal belongs.

By the way, as an example of a technique for realizing such an ultra-low distortion amplifier suitable for amplification of a multicarrier signal, there is a so-called FF (Feed-forward) amplification system (see, for example, Patent Documents 1 and 2).
Therefore, the FF amplification system, that is, the FF amplifier will be described.
First, in this FF amplifier, the signal path from the signal input terminal to the signal output terminal through the main amplifier, that is, the signal path for transmitting the signal to be amplified and the amplified signal is described as the main line.

In addition, in this FF amplification system, a distortion detection path is provided that combines a signal branched from a point downstream of the main amplifier on the main line with a signal branched from a point upstream of the main amplifier on the main line. ing.
Therefore, a loop constituted by the main line and the distortion detection path is described as a distortion detection loop.
Then, in this distortion detection loop, the electrical length of the signal path through which both the signal transmitted through the main line and the signal transmitted through the distortion detection path are equal to each other, and both signals have the same amplitude and opposite phase. If so, the signal component corresponding to the distortion generated in the main amplifier and its peripheral circuits can be extracted by canceling the carrier wave component by the above-described signal combination.

In this FF amplification method, a distortion compensation path is further provided to recombine a signal extracted by the distortion detection loop, that is, a signal corresponding to distortion, with a signal on the main line.
Therefore, if a loop composed of the main line and the distortion compensation path at this time is described as a distortion compensation loop, the signal delay in the distortion compensation loop is compensated on the main path, and the signal on the main path is If the amplitude and phase are adjusted appropriately in the distortion compensation loop so that the included distortion component and the distortion signal obtained by the distortion detection loop have the same amplitude and opposite phase, the signal recombination described above is performed. By operation, distortion generated in the main amplifier can be compensated.
This is realized by an FF type distortion high-frequency amplifier, which will be hereinafter referred to as an FF amplifier.

By the way, for example, in a base station apparatus of a mobile communication system, when a signal group having multicarrier signals of a plurality of passbands is amplified using this FF amplifier, usually, as shown in FIG. 2. Description of the Related Art Conventionally, an FF distortion compensating high frequency amplifying apparatus using FF amplifiers connected in parallel and connected to an antenna end has been used.
Here, this conventional technology will be described. This is applied to, for example, a base station apparatus of a mobile communication system, and a multicarrier signal to be wirelessly transmitted by the base station apparatus is amplified by a main amplifier, and the amplification is performed. This is to compensate for the distortion generated at the time.

  At this time, the multi-carrier signal input to the FF amplifier has two different signal bands having different frequency bands and separated from each other, that is, the input signal group of the frequency band A and the frequency band B. In this case, in the case of the FF distortion compensating high-frequency amplifier according to this prior art, the FF amplifiers applied to the respective bands are connected in parallel, and the outputs are coupled by a duplexer. To connect to.

  Therefore, according to the FF distortion compensating high-frequency amplification device according to this conventional technique, distortion generated during amplification can be compensated by being applied to a base station device of a mobile communication system.

JP 2003-283259 A JP 2005-323335 A

The above prior art does not give consideration to the existence of loss due to a duplexer for coupling the outputs of a plurality of FF high-frequency amplifiers, and there is a problem in reducing loss.
In the prior art, as apparent from FIG. 3, for example, the outputs of the A-band FF amplifier 1 and the B-band FF amplifier 2 are combined by the duplexer 3, so the loss is reduced due to the loss caused by the duplexer. Will cause problems.

  An object of the present invention is to provide a feedforward distortion-compensated high-frequency amplifier that can be applied to amplification of a wideband signal composed of a plurality of passbands such as a multicarrier signal to reduce loss.

  The above object is provided with first and second feedforward amplifying means each including a distortion detection loop and a distortion compensation loop, and these two systems of feedforward amplifying means amplify input signals in different frequency bands. In the feedforward distortion compensating high-frequency amplifier, the first bandpass filter connected to the main line output of the distortion detection loop of the first feedforward amplification unit, and the main line of the distortion detection loop of the second feedforward amplification unit A second band-pass filter connected to the output; a combiner connected to the output of the first band-pass filter and the output of the second band-pass filter; And a distortion compensation loop of the second feedforward amplification means And definitive main line is achieved as are commonly by the synthesizer.

Here, first, in order to solve the above-mentioned problems of the prior art, each pass band is amplified as it is, instead of using an FF amplifier for each pass band to synthesize outputs in a duplexer. A single FF amplifier may be used.
However, it is difficult to realize a wideband amplifier that amplifies a plurality of different bands together, and even if realized, electrical characteristics such as power efficiency and power gain are deteriorated as compared with a narrowband amplifier. After all, it does not solve the problems of the prior art.

Further, in this case, since the band-pass filter that passes only each pass band is not used, unnecessary waves are also amplified, and other devices are illegally operated, causing problems in operation.
Therefore, in the present invention, the duplexer portion of the FF amplifying device is not provided outside the FF amplifying device, but is positioned in the distortion compensation loop, and the delay necessary for the original delay adjuster in the distortion compensation loop. A part of the time is provided by the duplexer portion, and thus, in the conventional configuration, the duplexer that is installed outside the FF amplifying device and causes a loss of output is Thus, it is included in the delay part that originally caused the loss, so that the output loss can be reduced.

As a result, according to the present invention, in the amplifying apparatus that amplifies a multicarrier signal having a plurality of passbands, the duplexer connected to the antenna end can be eliminated, and thus the object can be achieved as described above.
At this time, according to the present invention, the distortion compensation loop includes the same number of distortion amplification systems as the input signal groups corresponding to each input signal group, and amplifies the distortion for each input signal group by the auxiliary amplifier for each distortion amplification system. Therefore, for example, it is possible to perform distortion compensation with high accuracy for a plurality of input signal groups without increasing the frequency band characteristics of the auxiliary amplifier used for amplifying the distortion detected by the distortion detection loop. And

The plurality of signal groups at this time have different frequency bands, and various frequency bands may be used as the frequency bands of the respective signal groups. As a specific example, frequency bands that are separated from each other are used as the frequency bands of the respective signal groups.
In this case, various numbers may be used as the number of the plurality of signal groups.
Here, each signal group may have, for example, a frequency bandwidth. For example, a signal having a single frequency may be used as the signal group referred to in the present invention. Is also included.

Various configurations may be used for the distortion detection loop configuration and the distortion elimination loop configuration at this time.
Similarly, various types of amplifiers may be used for the main amplifier. For example, it is conceivable to use a common amplifier that can amplify signals of a plurality of frequencies together.
Here, the distortion detected by the distortion detection loop includes distortion for each signal group, that is, distortion generated by amplifying each signal group by the main amplifier.

As the distortion for each input signal group, for example, third order distortion (upper third order distortion) generated in the upper (high frequency side) frequency band with respect to each input signal group, or each input signal group. In contrast, there is a third-order distortion (lower third-order distortion) generated in the lower (low frequency side) frequency band.
At this time, in the distortion compensation loop, various precisions may be used as the precision when removing the distortion from the amplified signal by the main amplifier as long as it is practically effective.

Various distortion amplification systems may be used in various configurations.
At this time, if the total distortion for each input signal group amplified by all the distortion amplification systems is removed from the amplified signal by the main amplifier, the distortion generated by the main amplifier for all the input signal groups from the amplified signal. Can be removed.

  A configuration example of the distortion compensation loop at this time includes a distribution means configured to distribute, for example, a distortion detected by the distortion detection loop to each distortion amplification system, and a distortion amplification system. It is conceivable to include a synthesizing means composed of, for example, a synthesizer for summing the distortion for each input signal group amplified by the auxiliary amplifier.

Here, in the feedforward distortion compensation high-frequency amplification device (FF amplification device) according to the present invention, as one configuration example, each distortion amplification system included in the distortion compensation loop is a filter that extracts distortion of an input signal group corresponding to each. The distortion extracted by the filter is amplified by an auxiliary amplifier.
As a result, in each distortion amplification system, distortion of each input signal group to be amplified can be extracted by a filter, and therefore unnecessary frequency components can be removed.

  Various filters may be used as the filter at this time. As a specific example, for each distortion amplification system filter, the frequency band of the distortion to be amplified by the respective distortion amplification system and the frequency band signal of the input signal group corresponding to the distortion are extracted, and these are extracted. A filter having such a characteristic as to remove a signal in a frequency band other than is used.

Here, in the FF amplifying device according to the present invention, as one configuration example, each distortion amplification system included in the distortion compensation loop is configured as follows. That is, in each distortion amplification system included in the distortion compensation loop, the band pass filter extracts the distortion of the corresponding input signal group, and the amplitude changer changes the amplitude of the distortion extracted by the band pass filter, thereby changing the phase. The amplifier changes the phase of the distortion extracted by the band pass filter, and the auxiliary amplifier amplifies the distortion whose phase is changed by the phase changer when the amplitude is changed by the amplitude changer.
Accordingly, in each distortion amplification system, when the distortion of the input signal group corresponding to each distortion amplification system is amplified by the auxiliary amplifier, the distortion can be controlled by changing the amplitude and phase of the distortion.

Therefore, the FF amplification device according to the present invention includes, for example, a base station device or a relay station provided in a mobile communication system such as a mobile phone system, a simple mobile phone system (PHS), and a multimedia broadcasting service. Suitable for equipment.
As an example, in a base station device or the like to which the FF amplifier according to the present invention is applied, as a result of having the above configuration, a signal such as a multicarrier for a mobile station device that is a communication partner is amplified by the FF amplifier. Thus, the distortion generated during the amplification is compensated, and the amplified signal is wirelessly transmitted to the communication partner.

Various configurations may be used as configurations of the mobile communication system, the base station device, the relay station device, the mobile station device, and the like at this time.
As a communication method at this time, for example, CDMA (Code Division
There are various communication methods such as a multiple access (TDMA) method, a time division multiple access (TDMA) method, a frequency division multiple access (FDMA) method, an orthogonal frequency division multiplexing access (OFDMA) method, and any method may be used. .

  According to the feedforward distortion-compensated high-frequency amplifier (FF amplifier) according to the present invention, a plurality of signal groups each having a different frequency band are input, and the plurality of input signals are grouped in a main band for each band in the distortion detection loop. Distortion compensation in a configuration in which distortion generated in the main amplifier is detected by the amplifier, and distortion generated in the main amplifier is detected. In the distortion compensation loop, distortion generated in the main amplifier due to distortion detected by the distortion detection loop is removed from the amplified signal by the main amplifier The loop is composed of the same number of distortion amplification systems as the input signal group, and distortions of the input signals amplified by the plurality of distortion amplification systems are combined to remove distortion signals generated in the main amplifier.

  As described above, in the present invention, since a duplexer and a coaxial delay line for synthesizing the frequency band are provided on the main line of the main amplifier output, for example, the frequency band characteristics of the auxiliary amplifier of each distortion amplification system need not be widened. As a result, it is not necessary to use the antenna duplexer after the distortion-compensating high-frequency amplifier. As a result, the duplexer connected to the antenna end can be deleted in the amplification device that amplifies the multicarrier signal having a plurality of pass bands. Therefore, it is possible to reduce the loss generated in the duplexer that passes through the required frequency band and synthesizes. Therefore, the efficiency of the amplifying device can be substantially increased without reducing the output power. .

At this time, in the FF amplifying device according to the present invention, one configuration example is as follows.
That is, first, in each distortion amplification system of the distortion compensation loop, the bandpass filter extracts the distortion of the input signal group corresponding to each, and the amplitude changer changes the amplitude of the distortion extracted by the bandpass filter, The phase changer changes the phase of the distortion extracted by the bandpass filter, and the auxiliary amplifier changes the amplitude by the amplitude changer and amplifies the distortion whose phase has been changed by the phase changer. When the distortion of the input signal is amplified by the auxiliary amplifier in each distortion amplification system, the amplitude and phase of the distortion can be controlled.

1 is a block diagram showing a first embodiment of a feedforward distortion-compensated high-frequency amplifier according to the present invention. It is a block diagram which shows 2nd Embodiment of the feedforward distortion compensation high frequency amplifier which concerns on this invention. It is a block diagram which shows an example of the feedforward distortion compensation high frequency amplifier by a prior art.

Hereinafter, a feedforward distortion compensating high-frequency amplifier according to the present invention will be described in detail with reference to embodiments shown in the drawings.
Here, FIG. 1 is a first embodiment of the present invention, which applies a feedforward distortion compensating high frequency amplification device (FF amplification device) according to the present invention to a base station device of a mobile communication system. This is an embodiment in which a multi-carrier signal to be wirelessly transmitted by a base station apparatus is amplified by a main amplifier to compensate for distortion generated during the amplification.

In the case of this embodiment, the multi-carrier signal input thereto has two frequency groups having different frequency bands and frequency bands separated from each other, that is, an A-band input signal group and a B-band. The case where it consists of the following input signal group is shown.
As shown in the figure, the FF amplifying apparatus according to this embodiment includes a distortion detection loop for two different frequency bands between two signal input terminals 100 and 200 and a single signal output terminal 150, and 2 It consists of a distortion compensation loop that combines different frequency bands of the group.

First, the distortion detection loop includes directional couplers (hybrid circuits) 110, 120, 210, and 220.
Then, between the first directional coupler 110 for A band and the second directional coupler 120 for A band, the first variable phase shifter 111 and the first variable attenuation are provided on one line on the upper side. 112 and a first main amplifier (first amplifier) 113, and a first coaxial delay line 115 is provided on the other line on the lower side.
Further, between the first directional coupler 210 for B band and the second directional coupler 220 for B band, a first variable phase shifter 211 and a first variable attenuator are provided on one line. 212 and a first main amplifier (first amplifier) 213, and a first coaxial delay line 215 is provided on the other line.

Next, the distortion compensation loop is divided into a main line portion that combines two different frequency bands with a duplexer and a distortion compensation path that operates each of the two different frequency bands.
First, in the A band of the main line portion, the main line output of the A band second directional coupler 120 is connected to the BPF 301 of the A band, and in the B band of the main line portion, the B band second directional coupler. 220 main line outputs are connected to the BPF 302 in the B band. BPF is a band pass filter.

At this time, the A-band BPF 301 and the B-band BPF 302 are built in the duplexer 30, whereby the duplexer 30 is included in the A-band frequency band and the B-band frequency band. The signal is passed, and the A-band signal and B-band signal that have passed through are combined and output to the main line.
Therefore, the duplexer 30 serves to share the main line in the A-band distortion compensation loop and the main line in the B-band distortion compensation loop.
The output of the duplexer 30 is connected to the main line input of the AB shared directional coupler 133 via the coaxial delay line 305.
Here, the AB shared directional coupler 133 is a directional coupler that synthesizes the main line and the distortion compensation path. Therefore, the function is the same as the directional coupler 130 in the prior art of FIG. is there.

  Next, in the A-band distortion compensation path, a coupler 124, an A-band second variable phase shifter 121, an A-band second variable attenuator 122, and an A-band auxiliary amplifier 123 are provided. In the distortion compensation path, a coupler 224, a B-band second variable phase shifter 221, a B-band second variable attenuator 222, and a B-band auxiliary amplifier 223 are provided. Are connected to the AB shared directional coupler 133.

  Here, the coupler 124 detects the distortion level detected from the A-band distortion detection loop, the coupler 224 detects the distortion level detected from the B-band distortion detection loop, and the combiner 310 uses the AB2 type. , Ie, the outputs of the A-band auxiliary amplifier 123 and the B-band auxiliary amplifier 223, and in this case also, the directional couplers 110, 133, and 210 function as dummy loads. Terminating resistors R110, R133, and R210 are provided.

The output of the AB shared directional coupler 133 is connected to the AB band shared signal output terminal 150 via the A band pilot signal detecting coupler 135 and the B band pilot signal detecting coupler 136.
Therefore, also in this embodiment, each amplified signal is output from the AB band shared signal output terminal 150 to the transmitting antenna.
Here, reference numeral 400 denotes a control unit, which includes couplers 135 and 136 and a control signal generation circuit, and constitutes a feedback control system using the pilot signal Pa and pilot signal Pb, thereby compensating for distortion generated during amplification. To do.
Therefore, hereinafter, the control by the control unit 400 will be described in more detail.

  First, in the case of this embodiment, for the A band, one line between the A band first directional coupler 110 and the A band second directional coupler 120 and the second A band band. One line between the directional coupler 120 and the AB shared directional coupler 133 forms a main line, and then the first A-band directional coupler 110 and the second A-band directional coupler. The other line between 120 is a distortion detection path, and the other line between the A-band second directional coupler 120 and the AB shared directional coupler 133 forms a distortion compensation path. Has been.

  Therefore, a distortion detection loop is formed by a loop constituted by one line (main line) between the A-band first directional coupler 110 and the A-band second directional coupler 120 and a distortion detection path. L1 is formed, and a distortion compensation loop L2 is formed by a loop composed of one line (main line) between the A-band second directional coupler 120 and the AB shared directional coupler 133 and a distortion compensation path. Is formed.

  Similarly, for the B band, one line between the first directional coupler 210 for the B band and the second directional coupler 220 for the B band, and the second directional coupler 220 for the B band, The main line is formed by one line between the AB shared directional coupler 133 and is distorted by the other line between the first directional coupler 210 for the B band and the second directional coupler 220 for the B band. A detection path is configured, and a distortion compensation path is configured by the other line between the B-band second directional coupler 120 and the AB shared directional coupler 133.

Therefore, a strain detection loop L3 is formed by a loop composed of one line (main line) between the first directional coupler 110 for A band and the second directional coupler 120 for A band and a path for strain detection. The distortion compensation loop L4 is formed by a loop formed by one line (main line) between the second directional coupler 220 for the B band 220 and the AB shared directional coupler 133 and the distortion compensation path. Yes.
The distortion compensation loops L3 and L4 are configured such that the main line path is synthesized and shared by the duplexer 30, which is a feature of this embodiment.

Next, the operation of this embodiment will be described.
First, in the distortion detection loop L1 related to the A band, a signal is input from the A band signal input terminal 100 and is distributed by the first directional coupler 110 for the A band.
Then, one of the distributed signals is input to the A-band second directional coupler 120 via the variable phase shifter 111, the variable attenuator 112, and the A-band main amplifier 113. At this time, the pilot signal Pa generated by the pilot signal generator of the control unit 400 is injected immediately before the A-band main amplifier 113.

The other signal (distortion extraction FF signal) distributed by the first A band directional coupler 110 is input to the A band combiner 120 via the delay circuit 115, where By combining with a part of the output signal of the main amplifier 113, a distortion signal is detected (distortion signal detection).
At this time, the delay time by the delay circuit 115 is set to coincide with the delay time given by the variable phase shifter 111, the variable attenuator 112, and the A-band main amplifier 113.

In addition, the amplitude and phase of the two types of carrier components of the two signals synthesized by the A-band second directional coupler 120 are made the same amplitude by the variable phase shifter 111, and the opposite phase by the variable attenuator 112. The
At this time, the control unit 400 controls the variable phase shifter 111 and the variable attenuator 112 based on the detection result of the coupler 135 so that only the distortion component generated in the A-band main amplifier 113 is extracted as a detected distortion signal. .
That is, the control device 400 sets the variable phase shifter 111 and the variable attenuator 112 based on the detection result of the coupler 135 so that the frequency level of the carrier component of the signal input from the A-band input terminal 100 is minimized. To control.

In the distortion compensation loop L2, the output signal of the A-band main amplifier 113 is supplied to the AB shared directional coupler 133 via the A-band second directional coupler 120, the A-band BPF 301, and the delay circuit 305. On the other hand, the distortion signal detected by the distortion detection loop L1 is sent to the AB shared directional coupler 133 via the variable phase shifter 121, the variable attenuator 122, and the A-band auxiliary amplifier 123. FF signal).
Therefore, the AB shared directional coupler 133 removes the distortion input to the output signal of the A-band main amplifier 113 input via the A-band BPF 301 and the delay circuit 305 via the A-band auxiliary amplifier 123. A low distortion output signal generated by combining the signals is output via the output terminal 150.

At this time, the delay time due to the A-band BPF 301 and the delay circuit 305 matches the delay time given by the coupler 124, the variable phase shifter 121, the variable attenuator 122, the A-band auxiliary amplifier 123, and the combiner 310. Is set to
At this time, the distortion components of the two signals synthesized by the AB shared directional coupler 133 are reversed in phase while maintaining the same phase and the same amplitude by the variable phase shifter 121 and the variable attenuator 122. .

  At this time, the control unit 400 controls the variable phase shifter 121 and the variable attenuator 122 to minimize distortion component leakage with respect to the low distortion output signal output from the AB shared directional coupler 133 to the output terminal 150. In other words, the amount of phase shift by the variable phase shifter 121 and the amount of attenuation by the variable attenuator 122 are adjusted so that the level of the pilot signal Pa detected from the coupler 135 is minimized.

Next, in the distortion detection loop L3 for the B band, a signal is input from the B band signal input terminal 200 and distributed by the first directional coupler 210 for B band.
Then, one of the distributed signals is input to the B-band second directional coupler 220 via the variable phase shifter 211, the variable attenuator 212, and the B-band main amplifier 213. At this time, the pilot signal Pb generated by the pilot signal generator of the control unit 400 is injected immediately before the B-band main amplifier 213.

The other signal (distortion extraction FF signal) distributed by the first B band directional coupler 210 is input to the B band combiner 220 via the delay circuit 215, where By combining with a part of the output signal of the main amplifier 213, a distortion signal is detected (distortion signal detection).
At this time, the delay time by the delay circuit 215 is set to coincide with the delay time given by the variable phase shifter 211, the variable attenuator 212 and the B-band main amplifier 213.

In addition, the amplitude and phase of the carrier components of the two signals synthesized by the B-band second directional coupler 220 are made the same amplitude by the variable phase shifter 211 and reversed by the variable attenuator 212. The
At this time, the control unit 400 controls the variable phase shifter 211 and the variable attenuator 212 based on the detection result of the coupler 136 so that only the distortion component generated in the B-band main amplifier 213 is extracted as the detected distortion signal. .
That is, the control device 400 sets the variable phase shifter 211 and the variable attenuator 212 based on the detection result of the coupler 136 so that the frequency level of the carrier component of the signal input from the B-band input terminal 200 is minimized. Control.

The distortion compensation loop L4 supplies the output signal of the B-band main amplifier 213 to the AB shared directional coupler 133 via the B-band second directional coupler 220, the B-band BPF 302, and the delay circuit 305. On the other hand, the distortion signal detected by the distortion detection loop L3 is sent to the AB shared directional coupler 133 via the variable phase shifter 221, the variable attenuator 222, and the B-band auxiliary amplifier 223. FF signal).
Therefore, the AB shared directional coupler 133 removes the distortion signal input via the B-band auxiliary amplifier 223 from the output signal of the B-band main amplifier 213 input via the B-band BPF 302 and the delay circuit 305. A low distortion output signal generated by combining the signals is output via the output terminal 150.

At this time, the delay time due to the B-band BPF 302 and the delay circuit 305 matches the delay time given by the coupler 224, the variable phase shifter 221, the variable attenuator 222, the B-band auxiliary amplifier 223, and the combiner 310. Is set to
At this time, the distortion components of the two signals synthesized by the AB shared directional coupler 133 are reversed in phase while maintaining the same phase and the same amplitude by the variable phase shifter 121 and the variable attenuator 122. .

At this time, the control unit 400 controls the variable phase shifter 221 and the variable attenuator 222 to minimize distortion component leakage with respect to the low distortion output signal output from the AB shared directional coupler 133 to the output terminal 150. In other words, the amount of phase shift by the variable phase shifter 221 and the amount of attenuation by the variable attenuator 222 are adjusted so that the level of the pilot signal Pb detected from the coupler 135 is minimized.
At this time, the combiner 310 combines the output signals of the A-band auxiliary amplifier 123 and the B-band auxiliary amplifier 223 and outputs the combined result to the AB shared directional coupler 133.

A signal amplified by the A-band main amplifier 113 and the B-band main amplifier 213 is synthesized by the duplexer 30 and input via the delay circuit 305 to one input of the AB shared directional coupler 133. Thus, the distortion signal generated in the A-band main amplifier 113 and the B-band main amplifier 213 is removed, and the signal from which the distortion is removed is output from the AB shared directional coupler 133.
Therefore, in the present invention, the duplexer portion is configured in the distortion removal loop of the FF amplification device, and also serves as a delay adjuster of the distortion removal loop. In the conventional configuration, the loss of output is set outside the FF amplification device. In the present invention, the duplexer that has been included is included in the delay portion that originally caused the loss inside the FF amplifying device, so that the output loss is substantially reduced.

As a result, according to the present invention, in the amplifying apparatus that amplifies a multicarrier signal having a plurality of passbands, the duplexer connected to the antenna end can be eliminated, and thus the object can be achieved as described above.
At this time, according to the present invention, the distortion compensation loop includes the same number of distortion amplification systems as the input signal groups corresponding to each input signal group, and amplifies the distortion for each input signal group by the auxiliary amplifier for each distortion amplification system. Therefore, for example, even if the frequency band characteristics of the auxiliary amplifier used for amplifying the distortion detected by the distortion detection loop is not made to be an ultra-wideband, distortion compensation can be performed with respect to a plurality of input signal groups with high accuracy. .

At this time, as the A-band BPF 301 and the B-band BPF 302, for example, those having delay flatness and amplitude flatness are used as a preferable mode, and thereby the phase and amplitude of the signal to be processed are disturbed. This prevents the accuracy of distortion compensation from deteriorating.
According to this embodiment, for example, it is possible to perform distortion compensation in a simple and wide band as compared with the conventional FF amplifying apparatus shown in FIG. 3, and the loss after each main amplifier is reduced. As a result, a high-output and high-efficiency high-frequency amplifier can be realized.

Here, the A-band coupler 135 and the B-band coupler 136 will be described.
As described above, the A-band pilot signal Pa is injected from the control unit 400 into the main line. Therefore, the A-band pilot signal Pa is extracted from the main line output by the coupler 135.
Therefore, the control unit 400 takes in the A-band pilot signal Pa from the coupler 135, and, as described above, based on the detection result of the A-band pilot signal, the A-band variable phase shifter 121 and the variable attenuator 122 are provided. Control so that good distortion compensation is obtained with respect to distortion of the input signal in the A band.

Similarly, as described above, the B-band pilot signal Pb is injected from the control unit 400 into the main line. Therefore, the B-band pilot signal Pb is extracted from the main line output by the coupler 136.
Therefore, the control unit 400 takes in the B-band pilot signal Pb from the coupler 136, and based on the detection result of the B-band pilot signal Pb, as described above, the B-band variable phase shifter 221 and the variable attenuator. 222 is controlled so that good distortion compensation can be obtained with respect to the distortion of the input signal in the B band.

  Therefore, in this embodiment, in the case of the prior art, the duplexer (the duplexer 3) installed outside the FF amplifier is used as the duplexer 30 before the coaxial delay line 305 inside the FF amplifier. As a result, according to this embodiment, the output loss due to the presence of the duplexer is reduced, and therefore, from a plurality of passbands such as a multicarrier signal. The loss can be reduced by applying to the amplification of a wideband signal, for the following reason.

First, in the case of the prior art, the duplexer (the duplexer 3) is installed outside the FF amplifier, and as described above, this is the cause of the output loss.
On the other hand, in the embodiment of the present invention, there is a duplexer (the duplexer 30). However, it is provided outside the FF amplifying apparatus and before the coaxial delay line 305 inside the FF amplifying apparatus.
Here, the function of the coaxial delay line 305 is the delay given by the couplers 124 and 224, the variable phase shifters 121 and 221, the variable attenuators 122 and 222, the A-band auxiliary amplifiers 123 and 223, and the combiner 310. It is to give the same delay time as time.

Then, in the embodiment of the present invention, the delay time required for the coaxial delay line 305 includes the delay time due to the duplexer 30, that is, the delay time due to the BPF 301 in the A band, and the delay time due to the BPF 302 in the B band. Accordingly, the delay time required for the coaxial delay line 305 is reduced accordingly.
Here, the path from the A-band second directional coupler 120 to the AB shared directional coupler 133 and the path from the B-band second directional coupler 220 to the AB shared directional coupler 133, respectively. Since the transmission loss is determined by the delay time given by each path, even if the duplexer 30 is included here, the transmission loss remains the same.

Therefore, according to this embodiment, the loss due to the duplexer being installed in the FF amplifying device is included in the loss that inevitably exists in the FF amplifying device. It is equivalent to not existing.
At this time, since no duplexer is installed outside the FF amplifier, output loss due to the installation of the duplexer is eliminated, and as a result, a low-loss feedforward distortion compensated high-frequency amplifier can be obtained.

In this embodiment, in the distortion compensation loop, the same number of distortion amplification systems as the input signal group corresponding to each input signal group, that is, the couplers 124 and 224, the variable phase shifters 121 and 221, and the variable attenuators 122 and 222. The distortion for each input signal group is amplified by the auxiliary amplifier for each distortion amplification system, that is, the A-band auxiliary amplifiers 123 and 223. Therefore, according to this embodiment, for example, by the distortion detection loop Even if the frequency band characteristic of the auxiliary amplifier for amplifying the detected distortion is not made to be an ultra-wide band, it is possible to perform distortion compensation with high accuracy for a plurality of input signal groups. Can be suppressed.

Next, a second embodiment of the present invention will be described with reference to FIG.
At this time, the same parts as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted, and description will be made with an emphasis on different points.
First, the embodiment of FIG. 2 is an embodiment in the case where the distortion detection loop is shared by the A band and the B band in the FF amplification device including the distortion detection loop and the distortion compensation loop. Accordingly, the A-band first directional coupler 110, the A-band first variable phase shifter 111, the A-band first variable attenuator 112, the A-band main amplifier 113, and the A-band first amplifier. A distortion detection loop including the coaxial delay line 115 and the second directional coupler 120 for the A band is shared by the A band and the B band.

Accordingly, both the A-band and B-band signals are supplied to the signal input terminal 100, and are amplified by sharing one main amplifier 113.
First, one output of the distortion detection loop is supplied as it is from the directional coupler 120 to the main line of the distortion compensation loop including the BEF 303 and the coaxial delay line 305.
Here, BEF is a band elimination filter that removes unnecessary bands. Therefore, only the signals in the A band and the B band are supplied to the AB shared directional coupler 133.

On the other hand, the other output of the directional coupler 120 is input to the third directional coupler 126. The directional coupler 126 further distributes the distortion compensation section for the A band and the distortion compensation section for the B band. At this time, the input of the distortion compensation section for the A band and the B band An A-band BPF 301 and a B-band BPF 302 are provided at the inputs of the distortion compensators for use.
The directional coupler 126 is also provided with a termination resistor R126 that functions as a dummy load.

Therefore, the A-band distortion signal and the B-band distortion signal respectively detected by the distortion detection loop are input to the A-band distortion compensation unit and the B-band distortion compensation unit, respectively.
Here, the control of the distortion detection loop and the distortion compensation loop is the same as in the case of the first embodiment described with reference to FIG. 1, and control using the pilot signals Pa and Pb is performed.
Therefore, although detailed description is omitted, at this time, the pilot signals Pa and Pb are expressed as pilot signals P (a + b) here.

  In the embodiment of FIG. 2, since the distortion detection loop is shared by the A band and the B band, the directional coupler 110, the variable phase shifter 111, the variable attenuator 112, and the main amplifier 113 included therein are included. As for the coaxial delay line 115 and the directional coupler 120, it is necessary to use one corresponding to a wide band including the A band and the B band. However, since the frequency band of the distortion compensation loop is narrowed, the distortion compensation amount is reduced. In addition, the same effect as that of the first embodiment can be obtained in that the size can be increased and an external duplexer is not required.

Here, the FF amplifying device according to the present invention is not necessarily limited to the above embodiment, and various configurations may be used.
For example, it may be a method for executing the processing according to the present invention, or may be provided as a program for realizing such a method.
Here, the field of application of the present invention is not necessarily limited to the above embodiment, and can be applied to various other fields.

  The various processes performed in the FF amplifying device according to the present invention include, for example, when a processor executes a control program stored in a ROM (Read Only Memory) in a hardware resource including a processor and a memory. A controlled configuration may be used. For example, each functional unit for executing the processing may be configured as an independent hardware circuit.

  Further, the present invention can be grasped as a computer-readable recording medium such as a floppy (registered trademark) disk or a CD (Compact Disc) -ROM storing the above control program, or the program (itself). It is also possible to perform the processing according to the present invention by inputting a control program from a recording medium to a computer and causing the processor to execute it.

1 FF amplifier that amplifies frequency band A (conventional technology)
2 FF amplifier that amplifies frequency band B (prior art)
3 Duplexer (external duplexer for amplifiers 1 and 2)
30 Duplexer 31 A band pass filter (BPF)
32 B band bandpass filter (BPF)
100 Signal input terminal (A-band signal input terminal)
150 output terminal (A and B band shared signal output terminal)
110 A-band first directional coupler R110 Termination resistor 111 A-band first variable phase shifter 112 A-band first variable attenuator 113 A-band main amplifier 115 A-band first coaxial delay Line 120 A-band second directional coupler 121 A-band second variable phase shifter 122 A-band second variable attenuator 123 A-band auxiliary amplifier 124 A coupler 125 A for detecting A-band distortion level Coaxial delay line 126 for band distortion compensation loop Third directional coupler R126 Terminating resistor 130 Third directional coupler R130 for A band Terminating resistor 131 A band pilot signal detecting coupler 133 AB shared directional coupler 135 A-band pilot signal detection coupler 136 B-band pilot signal detection coupler 140 A-band controller (prior art)
200 B-band signal input terminal 210 B-band first directional coupler R210 Termination resistor 211 B-band first variable phase shifter 212 B-band first variable attenuator 213 B-band main amplifier 215 B Band first coaxial delay line 220 B band second directional coupler 221 B band second variable phase shifter 222 B band second variable attenuator 223 B band auxiliary amplifier 224 B band distortion Level detection coupler 225 B-band distortion compensation loop coaxial delay line 230 B-band third directional coupler R230 Termination resistor 231 B-band pilot signal detection coupler 240 B-band controller (prior art)
301 A band BPF (band pass filter)
302 B-band BPF (band pass filter)
305 Coaxial delay line 310 for distortion compensation loop Synthesizer 400 Control unit (present invention)

Claims (1)

First and second feedforward amplification means each having a distortion detection loop and a distortion compensation loop are provided, and these two systems of feedforward amplification means respectively feedforward distortion compensation for amplifying input signals in different frequency bands. In a high frequency amplifier,
A first bandpass filter connected to the main line output of the distortion detection loop of the first feedforward amplification means; and a second band connected to the main line output of the distortion detection loop of the second feedforward amplification means. A pass filter, and a synthesizer connected to the output of the first band pass filter and the output of the second band pass filter;
The main line in the distortion compensation loop of the first feedforward amplifying means and the main line in the distortion compensation loop of the second feedforward amplifying means are shared by the combiner. Compensation high-frequency amplifier.

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