阅读说明：本技术 功率放大电路
(Power amplifying circuit
) 是由 长谷昌俊 于 2019-01-21 设计创作，主要内容包括：本发明提供一种能够在增大输出功率的同时抑制交调失真的影响的功率放大电路。功率放大电路具备：分配器,对输入信号进行分配并输出到主路径和副路径；失真补偿电路,设置在副路径；合成器,对经由了主路径的输入信号的基波和经由了副路径的输入信号的二倍波进行合成；以及第1放大器,对从合成器输出的合成信号进行放大并输出放大信号,失真补偿电路包含：生成电路,生成输入信号的二倍波；滤波器电路,使基波衰减,并使二倍波通过；以及相位调整电路,对二倍波的相位进行调整。(The invention provides a power amplifier circuit capable of increasing output power and inhibiting influence of intermodulation distortion. The power amplifier circuit includes: a distributor which distributes an input signal and outputs the signal to a main path and a sub path; a distortion compensation circuit provided in the sub path; a synthesizer for synthesizing a fundamental wave of the input signal via the primary path and a double wave of the input signal via the secondary path; and a 1 st amplifier that amplifies the synthesized signal output from the synthesizer and outputs an amplified signal, the distortion compensation circuit including: a generation circuit that generates a double wave of an input signal; a filter circuit for attenuating the fundamental wave and passing the double wave; and a phase adjustment circuit for adjusting the phase of the double wave.)
1. A power amplification circuit is provided with:
a distributor which distributes an input signal and outputs the signal to a main path and a sub path;
a distortion compensation circuit provided in the sub path;
a synthesizer for synthesizing a fundamental wave of the input signal via the main path and a double wave of the input signal via the sub path; and
a 1 st amplifier amplifying the synthesized signal output from the synthesizer and outputting an amplified signal,
the distortion compensation circuit includes:
a generation circuit that generates a double wave of the input signal;
a filter circuit that attenuates the fundamental wave and passes the double wave; and
and a phase adjustment circuit for adjusting the phase of the double wave.
2. The power amplification circuit of claim 1,
the distortion compensation circuit further includes: a 2 nd amplifier for amplifying the amplitude of the double wave,
the 2 nd amplifier is disposed between the generation circuit and the phase adjustment circuit.
3. The power amplification circuit of claim 2,
the 2 nd amplifier amplifies the amplitude of the double wave so that a signal of a difference between the double wave and the fundamental wave and third-order intermodulation distortion generated in the 1 st amplifier cancel each other in an output of the 1 st amplifier.
4. The power amplification circuit of any one of claims 1 to 3,
the phase adjustment circuit converts the phase of the second harmonic wave so that the phase of the signal of the difference between the second harmonic wave and the fundamental wave and the phase of the third-order intermodulation distortion generated in the 1 st amplifier are substantially opposite phases in the output of the 1 st amplifier.
5. The power amplification circuit according to any one of claims 1 to 4, further comprising:
a 3 rd amplifier provided at a front stage of the distributor and outputting the input signal; and
and a double wave attenuation circuit provided between the divider and the synthesizer in the main path, for attenuating a signal of the frequency band of the double wave.
6. The power amplification circuit of claim 5,
the double wave attenuation circuit comprises: a 4 th amplifier amplifying the input signal output to the main path by the divider.
7. The power amplification circuit of any one of claims 1 to 6,
the filter circuit is formed outside a semiconductor chip on which the 1 st amplifier is formed.
Technical Field
The present invention relates to a power amplifier circuit.
Background
A mobile communication device such as a mobile phone is equipped with a power amplifier for amplifying power of a transmission signal. When a plurality of signals having close frequencies are supplied to such a power amplifier, for example, Inter-modulation Distortion (IMD) may occur in the plurality of signals, thereby deteriorating the linearity of the gain. Therefore, in order to suppress the influence of such intermodulation distortion, a technique has been proposed in which a harmonic is intentionally injected into a signal path to cancel the intermodulation distortion component. For example, patent document 1 discloses a distortion compensation power amplifier device for compensating for intermodulation distortion by distributing the output of a first-stage amplifier to a fundamental wave and a double-wave, adjusting the phase and amplitude of the double-wave, adding the resulting sum to the fundamental wave, and inputting the sum to a second-stage amplifier.
Prior art documents
Patent document
Patent document 1: U.S. patent application publication No. 2005/0242877 specification
Disclosure of Invention
Problems to be solved by the invention
In recent years, due to introduction of new communication standards such as 4G (4 th generation mobile communication system) and 5G (5 th generation mobile communication system), the number of frequency bands to be handled by a power amplifier circuit has increased, and the number of filter circuits has increased accordingly. This increases the insertion loss at the front end, and therefore, in order to compensate for this loss, there is an increasing demand for an increase in the output power of the transmission signal transmitted by the mobile phone. Therefore, as described above, when the harmonic is intentionally injected to compensate for the intermodulation distortion, the power of the injected harmonic needs to be increased as the output power of the transmission signal increases. However, in the device disclosed in patent document 1, since the double wave generated in the first-stage amplifier is injected, the power of the double wave may be insufficient for the power of the transmission signal.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a power amplifier circuit capable of increasing output power and suppressing the influence of intermodulation distortion.
Means for solving the problems
In order to achieve the above object, a power amplifier circuit according to one aspect of the present invention includes: a distributor which distributes an input signal and outputs the signal to a main path and a sub path; a distortion compensation circuit provided in the sub path; a synthesizer for synthesizing a fundamental wave of the input signal via the primary path and a double wave of the input signal via the secondary path; and a 1 st amplifier that amplifies the synthesized signal output from the synthesizer and outputs an amplified signal, the distortion compensation circuit including: a generation circuit that generates a double wave of an input signal; a filter circuit for attenuating the fundamental wave and passing the double wave; and a phase adjustment circuit for adjusting the phase of the double wave.
Effects of the invention
According to the present invention, it is possible to provide a power amplifier circuit capable of increasing output power and suppressing the influence of intermodulation distortion.
Drawings
Fig. 1 is a diagram showing a configuration example of a power amplifier circuit according to embodiment 1 of the present invention.
Fig. 2 is a diagram showing a spectrum of a signal supplied to the amplifier 111 of the subsequent stage.
Fig. 3 is a diagram showing a part of the frequency spectrum of the signal output from the amplifier 111 of the subsequent stage.
Fig. 4A is a graph showing simulation results of third-order intermodulation distortion in the power amplifier circuit according to embodiment 1 of the present invention and a comparative example.
Fig. 4B is a graph showing simulation results of third-order intermodulation distortion in the power amplifier circuit according to embodiment 1 of the present invention and a comparative example.
Fig. 5 is a graph showing simulation results of gain characteristics in the power amplifier circuit according to embodiment 1 of the present invention and a comparative example.
Fig. 6 is a diagram showing a configuration example of a power amplifier circuit according to embodiment 2 of the present invention.
Fig. 7 is a diagram showing an example of the configuration of a transmission module including the power amplifier circuit according to embodiment 1 of the present invention.
Fig. 8 is a diagram showing another configuration example of a transmission module including the power amplifier circuit according to embodiment 1 of the present invention.
Fig. 9 is a diagram showing an example of the configuration of a transmission module including the power amplifier circuit according to embodiment 2 of the present invention.
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same elements are denoted by the same reference numerals, and redundant description thereof is omitted.
Fig. 1 is a diagram showing a configuration example of a power amplifier circuit according to embodiment 1 of the present invention. The power amplifier circuit 100A shown in fig. 1 is mounted in a mobile communication device such as a mobile phone, for example, and amplifies power of a Radio-Frequency (RF) signal transmitted to a base station. The power amplifier circuit 100A amplifies power of a signal of a communication standard such as 2G (2 nd generation mobile communication system), 3G (3 rd generation mobile communication system), 4G (4 th generation mobile communication system), 5G (5 th generation mobile communication system), LTE (Long Term Evolution) -FDD (Frequency Division Duplex), LTE-TDD (Time Division Duplex), LTE-Advanced, and LTE-Advanced Pro, for example. Further, the frequency of the RF signal is, for example, in the order of several hundred MHz to several tens GHz. The communication standard and frequency of the signal amplified by the power amplifier circuit 100A are not limited to these.
The power amplification circuit 100A includes, for example, amplifiers 110 and 111, a divider 120, a combiner 130, matching circuits 140 and 141, a harmonic stop circuit 150, a distortion compensation circuit 160, an input terminal T1, and an output terminal T2. Further, the power amplification circuit 100A includes a main path P1 and a sub path P2.
The amplifier 110 (3 rd amplifier) and the amplifier 111 (1 st amplifier) amplify and output the input RF signal, respectively. That is, the power amplification circuit 100A amplifies power in two stages. Specifically, the amplifier 110 of the primary stage (driving stage) amplifies the RF signal RF1 input from the input terminal T1 via the matching circuit 140, and outputs the RF signal RF2 (input signal). The amplifier 111 of the subsequent stage (power stage) amplifies an RF signal RF3 (synthesized signal) synthesized by a synthesizer 130 described later and outputs an RF signal RF 4. The RF signals RF2 and RF4 include harmonics including a double wave generated by the amplification operation of the amplifiers 110 and 111, respectively. The amplifiers 110 and 111 are each formed of a Bipolar Transistor such as a Heterojunction Bipolar Transistor (HBT). Instead of the HBT, the amplifiers 110 and 111 may be formed of a Metal-oxide-semiconductor Field-effect transistor (MOSFET).
The divider 120 divides the RF signal RF2 (input signal) output from the amplifier 110 at the primary stage and outputs the divided signal to the main path P1 and the sub path P2. The main path P1 is a path from the input terminal T1 to the output terminal T2 via the matching circuit 141. The main path P1 is a fundamental wave F for the RF signal RF10The path of the passage. The sub-path P2 is a path from the distributor 120 to the synthesizer 130 via the distortion compensation circuit 160. The sub-path P2 is for generating a double wave 2F0The double wave 2F0For compensating for third-order intermodulation distortion generated in the amplifier 111 of the subsequent stage. The divider 120 is not limited to a coupler or the like, and may be configured to divide an RF signal. For example, the distributor 120 may be a branch point that branches the signal path into the main path P1 and the sub path P2.
Synthesizer 130 pairs fundamental wave F having passed main path P10And a doublewave 2F via a secondary path P20The RF signals RF3 (synthesized signal) are generated by synthesis. The generated RF signal RF3 is supplied to the amplifier 111 at the subsequent stage.
The Matching circuit 140 (MN: Matching Network) matches the impedance of the amplifier 110 with a circuit (not shown) provided at a preceding stage.
The matching circuit 141 is provided between the divider 120 and the synthesizer 130 in the main path P1, and matches the impedances of the amplifier 110 and the amplifier 111. The matching circuit 141 also has a function of attenuating Harmonic Distortion (HD) generated by the amplification operation of the amplifier 110. That is, the matching circuit 141 constitutes a specific example of a double attenuation circuit. This can suppress the supply of the double wave to the synthesizer 130 when passing through the main path P1. Specifically, the matching circuit 141 may be, for example, a Low Pass Filter (LPF) circuit having frequency characteristics of passing a fundamental wave and attenuating a double wave.
The harmonic termination circuit 150 is provided at the subsequent stage of the amplifier 111. The harmonic termination circuit 150, for example, shorts the double wave contained in the RF signal RF4 to ground. Thereby, the transmission signal attenuated by the double wave is output from the output terminal T2. The harmonic stop circuit 150 may have a function of matching impedances of the amplifier 111 and a circuit subsequent to the output terminal T2.
The distortion compensation circuit 160 is provided between the divider 120 and the combiner 130 in the sub path P2. The distortion compensation circuit 160 is a circuit for generating a double wave 2F intentionally injected for compensating third-order intermodulation distortion0And amplifies and outputs it. Specifically, the distortion compensation circuit 160 includes, for example, a harmonic generation circuit 200, a filter circuit 210, an amplifier 220, a phase adjustment circuit 230, and a matching circuit 240.
The harmonic generation circuit 200 generates a double wave 2F of the RF signal RF2 based on the RF signal RF2 supplied from the distributor 120 to the sub path P20. The harmonic generation circuit 200 may be configured by, for example, an amplifier that amplifies the RF signal RF 2. Alternatively, the harmonic generation circuit 200 may be configured by a frequency multiplier circuit that multiplies the fundamental wave F supplied from the distributor 120 to the sub path P20Becomes twice as high.
The filter circuit 210 is provided, for example, at a stage subsequent to the harmonic generation circuit 200. The filter circuit 210 has a fundamental wave F0Attenuating and doubling the wave 2F0The frequency characteristic of the pass. Thus, for example, when the harmonic generation circuit 200 at the preceding stage is formed of an amplifier, only the double wave 2F necessary for compensating for distortion can be extracted from the signal output from the amplifier0. In addition, the filter circuit 210 may use, for example, the fundamental wave F0Attenuating and doubling the wave 2F0High pass filter (HPF: Hig) for passingh PassFilter) circuit or band pass filter (BPF: band Pass Filter) circuit.
The amplifier 220 (2 nd amplifier) is provided, for example, at the subsequent stage of the filter circuit 210. The amplifier 220 provides a voltage doubler 2F to the voltage supplied via the filter circuit 2100Is amplified and supplied to the phase adjustment circuit 230. By providing the amplifier 220 in the distortion compensation circuit 160, when the level of the output power of the transmission signal is relatively large, the double wave 2F can be generated according to the level0Is increased. In addition, the output level of the harmonic generation circuit 200 satisfies the condition of being a double wave 2F0In the case of a desired level, the distortion compensation circuit 160 may not include the amplifier 220.
The phase adjustment circuit 230 is provided at a subsequent stage of the amplifier 220, for example. The phase adjusting circuit 230 generates a double wave 2F0Is adjusted to a phase suitable for distortion compensation and output.
The matching circuit 240 matches the impedances of the phase adjustment circuit 230 and the amplifier 111.
According to the above configuration, the distortion compensation circuit 160 can generate the double wave 2F intentionally injected into the input of the amplifier 1110. The order of the components included in the distortion compensation circuit 160 is not limited to this, and may be changed as appropriate. For example, the amplifier 220 may be provided at a stage subsequent to the phase adjustment circuit 230. The divider 120, the synthesizer 130, the matching circuits 140, 141, and 240, the harmonic stop circuit 150, the filter circuit 210, and the phase adjustment circuit 230 may each include an element such as an inductor and a capacitor, or may include a resonator using an elastic Wave such as a Surface Acoustic Wave (SAW) filter.
Next, the action of compensation of third-order intermodulation distortion will be described with reference to fig. 2 and 3. Fig. 2 is a graph showing a spectrum of a signal (i.e., the RF signal RF3 in fig. 1) supplied to the amplifier 111 of the subsequent stage. Fig. 3 is a diagram showing a part of a frequency spectrum of a signal (i.e., the RF signal RF4 in fig. 1) output from the amplifier 111 of the subsequent stage. In the graphs shown in fig. 2 and 3, the horizontal axis shows the frequency of the signal, and the vertical axis shows the Power Spectral Density (PSD).
As shown in fig. 2, the fundamental wave F via the main path P1 is supplied to the amplifier 111 at the subsequent stage0And a doublewave 2F via a secondary path P20. Here, let fundamental wave F0Involving two frequencies f close to each other1、f2(f1＜f2) The component (c). At this time, the two frequencies f are generated in the secondary path P21、f2Respective doublets, thus doublets 2F0Comprising two frequencies of 2f1、2f2The component (c). Like this, frequency f1、f2Signal and frequency 2f1、2f2And are added and supplied to the amplifier 111.
Then, as shown in fig. 3, the fundamental wave F is amplified by the amplification operation of the amplifier 111, and the output0The amplified signal of (a). In addition, the amplification operation of the amplifier 111 is performed on the fundamental wave F0The low frequency side of (2) generates a frequency of 2f1-f3Third order intermodulation distortion IM3LAt the fundamental wave F0Has a high-frequency side generation frequency of 2f2-f1Third order intermodulation distortion IM3H. The third order intermodulation distortion IM3L、IM3HAnd fundamental wave F0Frequency f of1、f2Since they are relatively close to each other, they are difficult to remove by a filter circuit or the like, and may cause deterioration in the linearity of the amplifier. In addition, in the amplifying operation of the amplifier 111, for example, a frequency of 2f may be generated1+f2、2f2+f1Other distortions such as third-order intermodulation distortion, but the frequency of these distortions is away from the fundamental wave F0Frequency f of1、f2Relatively far away, and therefore, the description is omitted here.
To compensate for closer proximity to the fundamental wave F0Third order intermodulation distortion IM3L、IM3HIn the present embodiment, the injection of the doublet 2F is intentionally performed0Thereby generating image cancellation third order intermodulation distortion IM3L、IM3HSuch compensation signal CSL、CSH. Specifically, at the synthesizer 130, fundamental wave F0And a doubler 2F0The added signals are input to an amplifier 111, thereby generating a signal having a double wave 2F0One frequency 2f of1And fundamental wave F0Of another frequency f2Frequency of difference (2 f)1-f2) Is compensated forL. In addition, 2F with a double wave is generated0Of another frequency 2f2And fundamental wave F0Of a frequency f1Frequency of difference (2 f)2-f1) Is compensated forH. These compensation signals CSL、CSHRespectively with third order intermodulation distortion IM3L、IM3HAre equal in frequency. In addition, the phase adjustment circuit 230 adjusts the frequency of the double wave 2F0Is transformed so that the compensation signal CSL、CSHPhase and third order intermodulation distortion IM3L、IM3HThe phases of (a) and (b) are substantially opposite phases in the output of the amplifier 111. Further, the amplifier 220 is used for the doubler 2F0So that the compensation signal CS is amplifiedL、CSHAmplitude of and third order intermodulation distortion IM3L、IM3HAre cancelled by each other in the output of the amplifier 111. Thus, as shown in FIG. 3, the third order intermodulation distortion IM3L、IM3HCompensated signal CSL、CSHAnd (4) counteracting. In addition, in fig. 3, in order to show the compensation signal CSL、CSHAnd third order intermodulation distortion IM3L、IM3HIs substantially in opposite phase, compensating signal CSL、CSHShown facing downward.
By the above-described operation, in the power amplifier circuit 100A, the third-order intermodulation distortion IM3 generated in the amplifier 111 can be suppressedL、IM3HThe influence of (c). Thus, according to the power amplifier circuit 100A, deterioration in linearity can be suppressed.
Further, according to the configuration disclosed in patent document 1, since the main path between the divider and the combiner does not include a circuit for attenuating a double wave, the double wave generated by the amplification operation of the first-stage amplifier passes through the main path. Thus, even if a double wave is generated in the sub path, the double wave passing through the main path and the double wave passing through the sub path may be cancelled out when added to the synthesizer. Therefore, the power of the double wave injected into the amplifier 111 may be insufficient. In this regard, in the present embodiment, the matching circuit 141 provided in the main path P1 also has a function of attenuating the double wave. Thus, in the present embodiment, a high-power double wave can be injected into the amplifier 111, compared to the configuration disclosed in patent document 1. Therefore, according to the power amplifier circuit 100A, the influence of the intermodulation distortion can be suppressed while increasing the output power.
Further, in the present embodiment, the distortion compensation circuit 160 includes a harmonic generation circuit 200 for generating a double wave. When the harmonic generation circuit 200 is formed of an amplifier, the amplifier can be designed to be dedicated to generation of a double wave. Therefore, as compared with a configuration in which the first-stage amplifier serves both for amplification of the fundamental wave and generation of the second harmonic as disclosed in patent document 1, a second harmonic having a large power can be generated. Further, in the present embodiment, the distortion compensation circuit 160 includes an amplifier 220 for further amplifying the amplitude of the generated double wave. Accordingly, the power amplifier circuit 100A can generate a high-power double wave as compared with the configuration disclosed in patent document 1, and can suppress the influence of intermodulation distortion while increasing the output power.
The components included in the power amplifier circuit 100A shown in fig. 1 do not necessarily have to be provided as separate circuits, and one circuit may have a plurality of functions. For example, the distortion compensation circuit 160 may be replaced with the filter circuit 210, and the phase adjustment circuit 230 may also function as the filter circuit 210.
Although the above-described embodiment has been described by taking as an example a case where the distortion compensation circuit 160 generates a doublet wave to compensate for third-order intermodulation distortion, it is also possible to compensate for higher-order intermodulation distortion. More generally, if the frequency is f in the amplifier 1111、f2Is amplified to generate a frequency of { (N +1) f1-Nf2And { (N +1) f2-Nf1The (2N +1) -order intermodulation distortion of (N is an integer of 1 or more). Therefore, harmonics of an integral multiple of the fundamental frequency are generated by the distortion compensation circuit 160, and these high-order intermodulation distortions can be cancelled.
Fig. 4A and 4B are graphs showing simulation results of third-order intermodulation distortion in the power amplifier circuit according to embodiment 1 of the present invention and a comparative example. Here, the comparative example is a configuration in which the distortion compensating circuit 160 is not provided in the power amplifying circuit 100A shown in fig. 1. Fig. 4A shows third-order intermodulation distortion on the lower frequency side than the fundamental wave, and fig. 4B shows third-order intermodulation distortion on the higher frequency side than the fundamental wave. In the graphs shown in fig. 4A and 4B, the horizontal axis shows the output power pout (dbm) of the transmission signal, and the vertical axis shows the output level (dBc) of the third-order intermodulation distortion with respect to the fundamental wave.
As shown in fig. 4A and 4B, in the present embodiment and the comparative example, when the output power exceeds a certain output power, the output power of the third-order intermodulation distortion rapidly increases on average. However, when the output power is compared when the distortion is-35 dBm, for example, in fig. 4A, the output power is about 31dBm in the comparative example, whereas about 32.5dBm in the present embodiment is improved by about 1.5dB compared to the comparative example. In fig. 4B, the value is about 30.5dBm in the comparative example, whereas about 32.5dBm in the present embodiment, which is improved by about 2.0dB compared to the comparative example. As can be seen from this, in the present embodiment, the influence of the intermodulation distortion is suppressed while increasing the output power.
Fig. 5 is a graph showing simulation results of gain characteristics in the power amplifier circuit according to embodiment 1 of the present invention and a comparative example. In the graph shown in fig. 5, the horizontal axis shows the output power pout (dbm) of the transmission signal, and the vertical axis shows the gain (dB).
As shown in fig. 5, although the overall gain is slightly lower in the present embodiment than in the comparative example, the section in which the gain is constant is expanded regardless of the increase in the output power Pout. Therefore, the linearity of the present embodiment is improved as compared with the comparative example. In the comparative example, the gain rapidly decreases when the output power exceeds about 30dBm, but in the present embodiment, the gain gradually decreases even when the output power exceeds about 30 dBm. From this, it is understood that the degradation of linearity can be suppressed by suppressing the influence of intermodulation distortion as shown in fig. 4A and 4B.
Fig. 6 is a diagram showing a configuration example of a power amplifier circuit according to embodiment 2 of the present invention. Note that in this embodiment, descriptions of common matters with embodiment 1 are omitted, and only differences will be described. In particular, the same operational effects based on the same structure will not be mentioned in each embodiment.
The power amplifier circuit 100B shown in fig. 6 is provided with an amplifier 300 and matching circuits 310 and 311 instead of the matching circuit 141, as compared with the power amplifier circuit 100A shown in fig. 1.
The amplifier 300 (4 th amplifier) is provided between the divider 120 and the combiner 130 in the main path P1, and amplifies and outputs the RF signal RF2 (input signal) divided by the divider 120. In addition, the amplifier 300 is designed to cope with the fundamental wave F0The frequency band of (a) is amplified. This can attenuate harmonics including a double wave generated by the amplification operation of the first-stage amplifier 110. That is, the amplifier 300 constitutes a specific example of the double wave attenuation circuit.
The matching circuits 310 and 311 match the impedances of the amplifier of the preceding stage and the amplifier of the subsequent stage, respectively.
As described above, the attenuation of the double wave in the main path P1 provided in the present embodiment is not limited to the matching circuit 141 shown in fig. 1, and may be constituted by the amplifier 300. With such a configuration, the power amplifier circuit 100B can also increase the output power and suppress the influence of the intermodulation distortion, as in the power amplifier circuit 100A. Further, since the power amplification circuit 100B includes the amplifiers 110, 300, and 111 having three stages, the output power of the transmission signal can be further increased as compared with the power amplification circuit 100A.
Fig. 7 is a diagram showing an example of the configuration of a transmission module including the power amplifier circuit according to embodiment 1 of the present invention.
As shown in the figure, the transmission module 300A includes a semiconductor chip 20A mounted on a module substrate 10A, a matching circuit 142, and bias networks 180 to 183. The power amplifier circuit 100A and the bias circuits 170 to 173 according to embodiment 1 are integrated on the semiconductor chip 20A.
The matching circuit 142 matches impedances of the power amplification circuit 100A provided at the front stage and a circuit (not shown) provided at the rear stage of the power amplification circuit 100A. The matching circuit 142 may be formed inside the semiconductor chip 20A.
The bias networks 180 to 183 supply power supply voltages to the amplifiers 110 and 111, the harmonic generation circuit 200, and the amplifier 220, respectively. The bias circuits 170 to 173 are supplied with the battery voltage Vbatt, and supply bias currents or bias voltages to the amplifiers 110 and 111, the harmonic generation circuit 200, and the amplifier 220 based on control signals Ctrl1 to Ctr14 supplied from the outside of the module board 10A, respectively.
By integrating the power amplifier circuit 100A including the distortion compensation circuit 160 and the bias circuits 170 to 173 on the same semiconductor chip 20A in this manner, the transmission module can be made smaller than a configuration in which the distortion compensation circuit 160 is formed outside the semiconductor chip 20A, for example.
Fig. 8 is a diagram showing another configuration example of a transmission module including the power amplifier circuit according to embodiment 1 of the present invention.
As shown in the figure, the transmission module 300B is different from the transmission module 300A in that the filter circuit 210 included in the distortion compensation circuit 160 is formed outside the semiconductor chip 20B. That is, in the present configuration example, the harmonic wave output from the harmonic wave generation circuit 200 is output once to the outside of the semiconductor chip 20B, and then returned to the semiconductor chip 20B again through the filter circuit 210.
In this configuration, when the filter circuit 210 is formed of, for example, a SAW filter, the cost can be reduced as compared with a configuration in which the filter circuit 210 is formed in the semiconductor chip 20B. In this case, the filter circuit 210 may be mounted on the module substrate 10B by a Surface Mount Device (SMD), for example.
Fig. 9 is a diagram showing an example of the configuration of a transmission module including the power amplifier circuit according to embodiment 2 of the present invention.
As shown in the figure, the transmission module 300C is different from the transmission module 300A in that a semiconductor chip 20C is provided instead of the semiconductor chip 20A, and a bias network 184 is further provided.
The semiconductor chip 20C includes the power amplifier circuit 100B according to embodiment 2 and bias circuits 170 to 174. The bias circuit 174 is supplied with a battery voltage Vbatt, and supplies a bias current or a bias voltage to the amplifier 300 based on a control signal Ctr15 supplied from the outside of the module substrate 10C. The bias network 184 supplies a supply voltage to the amplifier 300.
Even in this case, the power amplifier circuit 100B including the distortion compensation circuit 160 and the bias circuits 170 to 174 can be integrated on the same semiconductor chip 20C, thereby achieving a reduction in size of the transmission module. In the transmission module 300C, the filter circuit 210 may be formed outside the semiconductor chip 20C, as in the transmission module 300B.
The transmission modules 300A to 300C may be configured as high-frequency modules together with a reception module including a Low Noise Amplifier (LNA). The plurality of transmission modules 300A to 300C may constitute a multiband high-frequency module together with the plurality of reception modules. In this case, the plurality of modules each deal with signals of different frequency bands. The multiband high-Frequency module may include modules corresponding to an FDD (Frequency Division Duplex) system and a TDD (Time Division Duplex) system, respectively.
The exemplary embodiments of the present invention have been described above. The power amplifier circuits 100A and 100B include: a distributor 120 that distributes the RF signal RF2 and outputs the RF signal RF2 to a main path P1 and a sub path P2; a distortion compensation circuit 160 provided in the secondary path P2; a synthesizer 130 for synthesizing the fundamental wave F of the RF signal RF2 via the main path P10And a double wave 2F of the RF signal RF2 via the secondary path P20Synthesizing; and an amplifier 111 for amplifying the RF output from the synthesizer 130The signal RF3 amplifies and outputs an RF signal RF4, and the distortion compensation circuit 160 includes: the harmonic generation circuit 200 generates a double wave 2F of the RF signal RF20(ii) a Filter circuit 210 for filtering the fundamental wave F0Attenuate and make the double wave 2F0Passing; and a phase adjustment circuit 230 for adjusting the phase of the double wave 2F0Is adjusted. Thus, according to the power amplifier circuits 100A and 100B, a high-power double wave can be generated compared to a configuration in which the first-stage amplifier is used for both the amplification of the fundamental wave and the generation of the double wave. Therefore, the influence of intermodulation distortion can be suppressed while increasing the output power.
The distortion compensation circuit 160 is also provided with a circuit for compensating for the double wave 2F0The amplifier 220 is disposed between the harmonic generation circuit 200 and the phase adjustment circuit 230. Thus, according to the power amplifier circuits 100A and 100B, a larger power of a double wave can be generated than a configuration without the amplifier 220 for amplifying the double wave. Therefore, the influence of intermodulation distortion can be suppressed while increasing the output power.
In addition, the amplifier 220 couples the doubler 2F0Is amplified so that the doublet 2F0And fundamental wave F0The difference signal and the third order intermodulation distortion IM3 generated in the amplifier 111L、IM3HCancel each other out in the output of amplifier 111. Thus, when the level of the output power of the transmission signal is relatively large, the double wave 2F can be generated according to the level0Is increased.
In addition, the phase adjusting circuit 230 adjusts the doubler 2F0Is converted so that the doublet 2F0And fundamental wave F0The phase of the difference signal and the third order intermodulation distortion IM3 generated in the amplifier 111L、IM3HThe phase of (b) is substantially opposite to the phase of (d) at the output of the amplifier 111. Thus, the third order intermodulation distortion IM3L、IM3HCompensated signal CSL、CSHTherefore, the influence of intermodulation distortion can be suppressed.
The power amplifier circuit 100A further includes: an amplifier 110 disposed at a front stage of the distributor 120And outputs an RF signal RF 2; and a matching circuit 141 provided between the divider 120 and the synthesizer 130 in the main path P1 for making the double wave 2F0The signal attenuation of the frequency band of (a). This prevents the doublet wave passing through the main path P1 and the doublet wave passing through the sub path P2 from being cancelled by the combiner 130. Therefore, the power amplifier circuit 100A can inject a high-power double wave into the amplifier 111, compared to the configuration disclosed in patent document 1.
The power amplifier circuit 100B further includes: an amplifier 110 disposed at a front stage of the distributor 120 and outputting an RF signal RF 2; and an amplifier 300 amplifying the RF signal RF2 output to the main path P1 by the distributor 120. This prevents the doublet wave passing through the main path P1 and the doublet wave passing through the sub path P2 from being cancelled by the combiner 130. Therefore, the power amplifier circuit 100B can inject a high-power double wave into the amplifier 111, compared to the configuration disclosed in patent document 1. Further, since the power amplification circuit 100B includes the amplifiers 110, 300, and 111 having three stages, the output power of the transmission signal can be further increased as compared with the power amplification circuit 100A.
In the transmission module 300B, the filter circuit 210 is formed outside the semiconductor chip 20B in which the amplifier 111 is formed. When the filter circuit 210 is formed of, for example, a SAW filter, the cost can be reduced as compared with a configuration in which the filter circuit 210 is formed in the semiconductor chip 20B.
The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention can be modified or improved without departing from the gist thereof, and the present invention also includes equivalents thereof. That is, the embodiments to which design changes are appropriately applied to each embodiment by those skilled in the art are included in the scope of the present invention as long as the features of the present invention are provided. For example, the elements and their arrangement, materials, conditions, shapes, dimensions, and the like included in the embodiments are not limited to the illustrated elements and their arrangement, materials, conditions, shapes, dimensions, and the like, and can be appropriately modified. Further, the elements included in the respective embodiments can be combined as long as the technical feasibility is achieved, and embodiments combining them are also included in the scope of the present invention as long as the features of the present invention are included.
Description of the reference numerals
10A-10C: module substrate, 20A to 20C: semiconductor chip, 100A, 100B: power amplification circuit, 110, 111, 220, 300: an amplifier, 120: a dispenser, 130: synthesizer, 140, 141, 142, 240, 310, 311: matching circuit, 150: harmonic termination circuit, 160: distortion compensation circuit, 170 to 174: bias circuit, 180 ~ 183: bias network, 200: harmonic generation circuit, 210: filter circuit, 230: phase adjustment circuit, 300A to 300C: transmission module, T1: input terminal, T2: output terminal, P1: main path, P2: a secondary path.
