阅读说明：本技术 射频功率放大器及通信设备 (Radio frequency power amplifier and communication equipment ) 是由 孙亚楠 朱波 梁聪 于 2020-05-13 设计创作，主要内容包括：一种射频功率放大器及通信设备,射频功率放大器包括：功率放大单元、功率合成变压器以及匹配滤波电路,功率放大单元,第一输出端输出经过放大的第一差分信号,第二输出端输出经过放大的第二差分信号；功率合成变压器,初级线圈的第一输入端输入经过放大的第一差分信号,第二输入端输入经过放大的第二差分信号；次级线圈包括主次级线圈以及辅次级线圈,主次级线圈的第一端接地,第二端与射频功率放大器的输出端耦接；辅次级线圈,第一端与主次级线圈的第二端耦接,第二端与输出端匹配滤波电路耦接；匹配滤波电路,包括输入端匹配滤波电路以及输出端匹配滤波电路。上述方案能够在较宽的频率范围内实现一致的性能,并且具有较高的效率和谐波性能。(A radio frequency power amplifier and a communication device, the radio frequency power amplifier includes: the power amplifier unit comprises a first output end, a second output end and a matching filter circuit, wherein the first output end outputs an amplified first differential signal, and the second output end outputs an amplified second differential signal; the power synthesis transformer is characterized in that a first input end of a primary coil inputs an amplified first differential signal, and a second input end of the primary coil inputs an amplified second differential signal; the secondary coil comprises a main secondary coil and an auxiliary secondary coil, the first end of the main secondary coil is grounded, and the second end of the main secondary coil is coupled with the output end of the radio frequency power amplifier; the first end of the auxiliary secondary coil is coupled with the second end of the main secondary coil, and the second end of the auxiliary secondary coil is coupled with the output end matched filter circuit; and the matched filter circuit comprises an input end matched filter circuit and an output end matched filter circuit. The scheme can achieve consistent performance in a wider frequency range and has higher efficiency and harmonic performance.)

1. A radio frequency power amplifier, comprising: power amplification unit, power synthesis transformer and matched filter circuit, wherein:

in the power amplification unit, a first differential signal is input at a first input end, a second differential signal is input at a second input end, the first amplified differential signal is output at a first output end, and the second amplified differential signal is output at a second output end;

the power synthesis transformer comprises a primary coil and a secondary coil; the first input end of the primary coil inputs the amplified first differential signal, and the second input end of the primary coil inputs the amplified second differential signal; the secondary coil comprises a main secondary coil and an auxiliary secondary coil, wherein the first end of the main secondary coil is grounded, and the second end of the main secondary coil is coupled with the output end of the radio frequency power amplifier; the first end of the auxiliary secondary coil is coupled with the second end of the main secondary coil, and the second end of the auxiliary secondary coil is coupled with the output end matched filter circuit;

the matched filter circuit comprises an input end matched filter circuit and an output end matched filter circuit; the input end matching filter circuit is coupled with the first input end of the power synthesis transformer and the second input end of the power synthesis transformer; the output end matched filter circuit is coupled between the second end of the auxiliary secondary coil and the ground.

2. The radio frequency power amplifier of claim 1, wherein the input matched filter circuit comprises: a first sub-filter circuit and a second sub-filter circuit, wherein:

a first end of the first sub-filter circuit is coupled with a first input end of the power synthesis transformer and a first output end of the power amplification unit, and a second end of the first sub-filter circuit is grounded;

the first end of the second sub-filter circuit is coupled to the second input end of the power synthesis transformer and the second output end of the power amplification unit, and the second end is grounded.

3. The radio frequency power amplifier of claim 2, wherein the first sub-filter circuit comprises: a first capacitor; the first end of the first capacitor is coupled to the first input end of the power combining transformer and the first output end of the power amplifying unit, and the second end of the first capacitor is grounded.

4. The radio frequency power amplifier of claim 3, wherein the first sub-filter circuit further comprises: a first inductor; the first inductor is connected in series between the second end of the first capacitor and ground.

5. The radio frequency power amplifier of claim 2, wherein the second sub-filter circuit comprises: a second capacitor; the first end of the second capacitor is coupled to the second input end of the power combining transformer and the second output end of the power amplifying unit, and the second end of the second capacitor is grounded.

6. The radio frequency power amplifier of claim 5, wherein the second sub-filter circuit further comprises: a second inductor; the second inductor is connected in series between the second end of the second capacitor and ground.

7. The radio frequency power amplifier of claim 2, wherein the input matched filter circuit further comprises: a parasitic capacitance; the parasitic capacitor is coupled between the first output terminal of the power amplification unit and the second output terminal of the power amplification unit.

8. The radio frequency power amplifier of claim 1, wherein the output matched filter circuit comprises a third sub-filter circuit; and the first end of the third sub-filter circuit is coupled with the second end of the auxiliary secondary coil, and the second end of the third sub-filter circuit is grounded.

9. The radio frequency power amplifier of claim 8, wherein the third sub-filter circuit comprises: a third capacitor; and the first end of the third capacitor is coupled with the second end of the auxiliary secondary coil, and the second end of the third capacitor is grounded.

10. The radio frequency power amplifier of claim 8, wherein the third sub-filter circuit further comprises: a third inductor; the third inductor is connected in series between the second end of the third capacitor and ground.

11. The radio frequency power amplifier of claim 8 wherein the output matched filter circuit further comprises a fourth sub-filter circuit; and the first end of the fourth sub-matched filter circuit is coupled with the second end of the main secondary coil, and the second end of the fourth sub-matched filter circuit is coupled with the output end of the radio frequency power amplifier.

12. The radio frequency power amplifier of claim 11 wherein the fourth sub-filter circuit is an L C matched filter circuit.

13. The radio frequency power amplifier of claim 11, wherein the L C matched filter circuit comprises a fourth capacitor and a fourth inductor, wherein:

a first end of the fourth inductor is coupled with a second end of the main secondary coil, and a second end of the fourth inductor is coupled with an output end of the radio frequency power amplifier;

and the first end of the fourth capacitor is coupled with the second end of the fourth inductor, and the second end of the fourth capacitor is grounded.

14. The radio frequency power amplifier of claim 13, wherein the L C matching circuit further comprises a fifth inductor and a sixth inductor, wherein:

the fifth inductor is connected between the second end of the fourth capacitor and the ground in series;

the sixth inductor is connected in series between the first end of the fourth capacitor and the output end of the radio frequency power amplifier.

15. The radio frequency power amplifier of claim 14, wherein the L C matching circuit further comprises a fifth capacitor, a seventh inductor, and an eighth inductor, wherein:

a first end of the fifth capacitor is coupled to the second end of the sixth inductor, and a second end of the fifth capacitor is coupled to the first end of the seventh inductor;

a second end of the seventh inductor is grounded;

and a first end of the eighth inductor is coupled to the first end of the fifth capacitor, and a second end of the eighth inductor is coupled to the output end of the rf power amplifier.

16. The radio frequency power amplifier of any of claims 1 to 15, further comprising: a drive circuit; the input end of the driving circuit receives an input signal, the first output end of the driving circuit outputs the first differential signal, and the second output end of the driving circuit outputs the second differential signal.

17. A communication device, comprising: a radio frequency power amplifier as claimed in any one of claims 1 to 16.

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a radio frequency power amplifier and a communications device.

Background

In wireless communication, a user equipment needs to support a plurality of operating frequency bands (bands), especially in the fourth generation cellular mobile communication (L TE), the user equipment needs to support 40 operating frequency bands (bands), while the performance of a broadband power amplifier (PowerAmplifier, PA) varies with the operating frequency, and it is difficult to achieve a wide power frequency range, the L TE operating frequency is generally divided into a low frequency band (L B, 663 MHz-915 MHz), a medium frequency band (MB, 1710 MHz-2025 MHz), a high frequency band (HB, 2300 MHz-2696 MHz), and a L TE radio frequency front end also includes L B, HB, and three PAs, each power amplifier supports one frequency band, needs three broadband PA., especially L B relative frequency bandwidths, and the PAs are difficult to achieve high linearity and high efficiency in the whole frequency band, there are linearity and efficiency compromise processing in the design process, and the performance of different frequency bands is different.

Wireless communications place stringent requirements on the spurs of the transmitted spectrum. A filter connected after the PA has less harmonic rejection and therefore requires a lower output harmonic of the PA. The matching path of the PA should have filtering performance at the same time. Part of highly integrated radio frequency front-end chips (such as 2G front-end modules and NBIOT front-end modules) require that the matching filter circuit of the PA has high harmonic suppression performance at the same time, so that a filter does not need to be added behind the PA.

Designing a wideband power amplifier to achieve consistent and good performance within the power frequency range becomes a key and difficult point in the design of wideband PAs.

The broadband PA generally adopts a C LL C, L CC L and two-stage or multi-stage L C matching structure, a C LL C structure adopts a series capacitor to ground inductor to cascade a series inductor to a ground capacitor, a L CC L structure adopts a series capacitor to ground inductor to cascade a series capacitor to ground inductor, the two structures have the advantages of simpler structure and smaller insertion loss, and have the disadvantages of poor broadband performance consistency, inconsistent performance at different frequencies and poor harmonic performance.

The PA for realizing power synthesis and impedance conversion by adopting the transformer with the common structure has the advantages of relatively simple structure and poor consistency of broadband performance and harmonic performance because the broadband power amplifier is difficult to realize, and the PA for realizing power synthesis and impedance conversion by adopting the transformer cascade L C matching with the common structure has the advantages of good harmonic performance and realization of impedance conversion with the broadband consistency and the output cascade L C matching filter circuit because the transformer with the common structure and the input and output matching capacitor thereof have the disadvantages of compromise between the broadband performance consistency and insertion loss and large high-frequency point insertion loss.

Disclosure of Invention

The embodiment of the invention solves the problem of how to realize the consistency of the radio frequency power amplifier in a wider frequency range and has better harmonic performance and working efficiency.

To solve the above technical problem, an embodiment of the present invention provides a radio frequency power amplifier, including: power amplification unit, power synthesis transformer and matched filter circuit, wherein: in the power amplification unit, a first differential signal is input at a first input end, a second differential signal is input at a second input end, the first amplified differential signal is output at a first output end, and the second amplified differential signal is output at a second output end; the power synthesis transformer comprises a primary coil and a secondary coil; the first input end of the primary coil inputs the amplified first differential signal, and the second input end of the primary coil inputs the amplified second differential signal; the secondary coil comprises a main secondary coil and an auxiliary secondary coil, wherein the first end of the main secondary coil is grounded, and the second end of the main secondary coil is coupled with the output end of the radio frequency power amplifier; the first end of the auxiliary secondary coil is coupled with the second end of the main secondary coil, and the second end of the auxiliary secondary coil is coupled with the output end matched filter circuit; the matched filter circuit comprises an input end matched filter circuit and an output end matched filter circuit; the input end matching filter circuit is coupled with the first input end of the power synthesis transformer and the second input end of the power synthesis transformer; the output end matched filter circuit is coupled between the second end of the auxiliary secondary coil and the ground.

Optionally, the input end matched filter circuit includes: a first sub-filter circuit and a second sub-filter circuit, wherein: a first end of the first sub-filter circuit is coupled with a first input end of the power synthesis transformer and a first output end of the power amplification unit, and a second end of the first sub-filter circuit is grounded; the first end of the second sub-filter circuit is coupled to the second input end of the power synthesis transformer and the second output end of the power amplification unit, and the second end is grounded.

Optionally, the first sub-filter circuit includes: a first capacitor; the first end of the first capacitor is coupled to the first input end of the power combining transformer and the first output end of the power amplifying unit, and the second end of the first capacitor is grounded.

Optionally, the first sub-filter circuit further includes: a first inductor; the first inductor is connected in series between the second end of the first capacitor and ground.

Optionally, the second sub-filter circuit includes: a second capacitor; the first end of the second capacitor is coupled to the second input end of the power combining transformer and the second output end of the power amplifying unit, and the second end of the second capacitor is grounded.

Optionally, the second sub-filter circuit further includes: a second inductor; the second inductor is connected in series between the second end of the second capacitor and ground.

Optionally, the input end matched filter circuit further includes: a parasitic capacitance; the parasitic capacitor is coupled between the first output terminal of the power amplification unit and the second output terminal of the power amplification unit.

Optionally, the output end matched filter circuit includes a third sub-filter circuit; and the first end of the third sub-filter circuit is coupled with the second end of the auxiliary secondary coil, and the second end of the third sub-filter circuit is grounded.

Optionally, the third sub-filter circuit includes: a third capacitor; and the first end of the third capacitor is coupled with the second end of the auxiliary secondary coil, and the second end of the third capacitor is grounded.

Optionally, the third sub-filter circuit further includes: a third inductor; the third inductor is connected in series between the second end of the third capacitor and ground.

Optionally, the output end matched filter circuit further includes a fourth sub-filter circuit; and the first end of the fourth sub-matched filter circuit is coupled with the second end of the main secondary coil, and the second end of the fourth sub-matched filter circuit is coupled with the output end of the radio frequency power amplifier.

Optionally, the fourth sub-filter circuit is an L C matched filter circuit.

Optionally, the L C matched filter circuit includes a fourth capacitor and a fourth inductor, wherein a first end of the fourth inductor is coupled to the second end of the primary and secondary coil, a second end of the fourth inductor is coupled to the output end of the rf power amplifier, and a first end of the fourth capacitor is coupled to the second end of the fourth inductor, and a second end of the fourth capacitor is grounded.

Optionally, the L C matching circuit further includes a fifth inductor and a sixth inductor, wherein the fifth inductor is connected in series between the second end of the fourth capacitor and ground, and the sixth inductor is connected in series between the first end of the fourth capacitor and the output terminal of the rf power amplifier.

Optionally, the L C matching circuit further includes a fifth capacitor, a seventh inductor, and an eighth inductor, wherein a first end of the fifth capacitor is coupled to a second end of the sixth inductor, a second end of the fifth capacitor is coupled to a first end of the seventh inductor, a second end of the seventh inductor is grounded, a first end of the eighth inductor is coupled to a first end of the fifth capacitor, a second end of the eighth inductor is coupled to the output end of the rf power amplifier, and a second end of the eighth inductor is coupled to the output end of the rf power amplifier

Optionally, the radio frequency power amplifier further includes: a drive circuit; the input end of the driving circuit receives an input signal, the first output end of the driving circuit outputs the first differential signal, and the second output end of the driving circuit outputs the second differential signal.

The embodiment of the invention also provides communication equipment comprising the radio frequency power amplifier.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

the auxiliary secondary coil is added, so that the energy coupling path from input to output can be increased on the premise of not influencing the primary coil and the main secondary coil, and the influence of a small coupling coefficient k value on impedance transformation is reduced. According to the parameters such as the k values of the primary coil and the main secondary coil, the proper size and the k value of the auxiliary secondary coil are selected, so that the impedance conversion working frequency range of the power synthesis transformer can be effectively improved, and the loss of the power synthesis transformer is reduced. In addition, the main secondary coil and the auxiliary secondary coil of the power synthesis transformer and the matching filter circuit are cooperatively designed, so that the broadband impedance transformation and the filtering performance of the radio frequency power amplifier can be further improved.

Drawings

Fig. 1 is a circuit configuration diagram of a radio frequency power amplifier in an embodiment of the present invention;

fig. 2 is a circuit configuration diagram of another radio frequency power amplifier in the embodiment of the present invention;

fig. 3 is a circuit configuration diagram of a radio frequency power amplifier according to still another embodiment of the present invention;

fig. 4 is a circuit configuration diagram of a further radio frequency power amplifier in an embodiment of the present invention;

fig. 5 is a circuit configuration diagram of a radio frequency power amplifier according to still another embodiment of the present invention;

fig. 6 is a circuit configuration diagram of a further radio frequency power amplifier in an embodiment of the present invention;

fig. 7 is a circuit configuration diagram of a radio frequency power amplifier according to another embodiment of the present invention.

Detailed Description

As described above, in the prior art, the PA for power synthesis and impedance conversion is realized by adopting a transformer with a common structure, and only the transformer and an input/output matching capacitor thereof are adopted, so that the structure has the advantages of relatively simple structure and poor broadband performance consistency and harmonic performance, the PA for power synthesis and impedance conversion is realized by adopting the cascade L C matching of the transformer with the common structure, and the PA for power synthesis and impedance conversion is realized by adopting the transformer and an input/output matching capacitor thereof and an output cascade L C matching filter circuit.

In the embodiment of the invention, the auxiliary secondary coil is added, so that the energy coupling path from input to output can be added on the premise of not influencing the primary coil and the main secondary coil, and the influence of a smaller coupling coefficient k value on impedance transformation is reduced. According to the parameters such as the k values of the primary coil and the main secondary coil, the proper size and the k value of the auxiliary secondary coil are selected, so that the impedance conversion working frequency range of the power synthesis transformer can be effectively improved, and the loss of the power synthesis transformer is reduced. In addition, the main secondary coil and the auxiliary secondary coil of the power synthesis transformer and the matching filter circuit are cooperatively designed, so that the broadband impedance transformation and the filtering performance of the radio frequency power amplifier can be further improved.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

An embodiment of the present invention provides a radio frequency power amplifier, and refer to fig. 1. In an embodiment of the present invention, the radio frequency power amplifier may include: a power amplifying unit (powercell), a power combining transformer and a matched filter circuit.

In a specific implementation, the power amplification unit may include two input terminals and two output terminals. In the embodiment of the present invention, the first INPUT terminal of the power amplification unit may INPUT the first differential signal INPUT _ P, and the second INPUT terminal of the power amplification unit may INPUT the second differential signal INPUT _ N.

The power amplifying unit may amplify the INPUT first differential signal INPUT _ P and the INPUT second differential signal INPUT _ N, respectively, a first output terminal of the power amplifying unit may output the amplified first differential signal, and a second output terminal of the power amplifying unit may output the amplified second differential signal. The amplification factor of the first differential signal INPUT _ P and the second differential signal INPUT _ N may be determined by the amplification factor of the power amplification unit, and the amplification factor of the first differential signal INPUT _ P is the same as the amplification factor of the second differential signal INPUT _ N.

In a specific implementation, the first differential signal INPUT _ P and the second differential signal INPUT _ N may be obtained by performing differential processing on an INPUT signal INPUT to the rf power amplifier. Specifically, the principle and process of performing differential processing on the input signal may refer to the prior art, and are not described in detail in the embodiments of the present invention.

In a specific implementation, the power combining transformer may include a primary coil 11 and a secondary coil.

In the embodiment of the present invention, the first end of the primary coil 11 may be coupled to the first output end of the power amplifying unit, and the amplified first differential signal is input; a second terminal of the primary coil 11 may be coupled to a second output terminal of the power amplifying unit, and inputs the amplified second differential signal.

In the embodiment of the present invention, the secondary coil may include a main secondary coil 121 and an auxiliary secondary coil 122. A first end of the primary and secondary coil 121 is grounded, and a second end of the primary and secondary coil 121 is coupled to an OUTPUT of the rf power amplifier; a first terminal of the auxiliary secondary winding 122 is coupled to a second terminal of the main secondary winding 121, and a second terminal of the auxiliary secondary winding 122 is coupled to an output terminal matched filter circuit of the matched filter circuit.

That is to say, in the embodiment of the present invention, the secondary coil is composed of the primary secondary coil 121 and the auxiliary secondary coil 122, and the auxiliary secondary coil 122 and the output end matched filter circuit can be combined to form a power combining function.

In a particular implementation, the matched filter circuit may include an input matched filter circuit and an output matched filter circuit. The input matching filter circuit may be coupled to a first input of the power combining transformer and a first output of the power amplifying unit, and coupled to a second input of the power combining transformer and a second output of the power amplifying unit. The output matched filter circuit may be connected in series between the second terminal of the auxiliary secondary winding 122 and ground.

In a specific implementation, the input matched filter circuit may include a first sub-filter circuit and a second sub-filter circuit, wherein: a first terminal of the first sub-filter circuit may be coupled to a first input terminal of the power combining transformer and a first output terminal of the power amplifying unit, and a second terminal of the first sub-filter circuit may be grounded; the first terminal of the second sub-filter circuit may be coupled to the second input terminal of the power combining transformer and the second output terminal of the power amplifying unit, and the second terminal of the second sub-filter circuit may be grounded.

That is to say, in the embodiment of the present invention, corresponding filter circuits may be disposed at the first input end of the power combining transformer and the second input end of the power combining transformer, so as to perform corresponding matched filtering processing on the signal input to the power combining transformer.

In a specific implementation, the first sub-filter circuit may include a first capacitor C1, a first terminal of the first capacitor C1 may be coupled to the first input terminal of the power combining transformer and the first input terminal of the power amplifying unit, and a second terminal may be grounded.

In the embodiment of the present invention, to improve the harmonic filtering performance, the first sub-filter circuit may further include a first inductor L1, and the first inductor L1 may be disposed between the second terminal of the first capacitor C1 and ground.

Referring to fig. 2, a circuit structure diagram of another rf power amplifier in an embodiment of the invention is shown, in fig. 2, the first sub-filter circuit includes a first inductor L1 and a first capacitor C1, and the first inductor L1 is connected in series between the second end of the first capacitor C1 and ground.

In a specific implementation, the second sub-filter circuit may include a second capacitor C2, a first terminal of the second capacitor C2 may be coupled to the second input terminal of the power combining transformer and the second input terminal of the power amplifying unit, and a second terminal may be grounded.

In the embodiment of the present invention, to improve the harmonic filtering performance, the second sub-filter circuit may further include a second inductor L2, and the second inductor L2 may be disposed between the second terminal of the second capacitor C2 and ground.

With continued reference to fig. 2, the second sub-filter circuit includes a second inductor L2 and a second capacitor C2, and the second inductor L2 is connected in series between the second terminal of the second capacitor C2 and ground.

In a specific implementation, the capacitance to ground of the series inductance and the resonant frequency of the inductance may be in the vicinity of the second harmonic frequency of the power amplification unit.

That is, when the first sub-filter circuit includes the first capacitor C1 and the first inductor L1, the resonant frequency of the first capacitor C1 and the first inductor L1 is near the second harmonic frequency of the power amplification unit, correspondingly, when the second sub-filter circuit includes the second capacitor C2 and the second inductor L2, the resonant frequency of the second capacitor C2 and the second inductor L2 is near the second harmonic frequency of the power amplification unit.

Therefore, in a specific application, according to the second harmonic frequency of the power amplifying unit, the first capacitor C1 with a corresponding capacitance value and the first inductor L1 with a corresponding inductance value can be selected to realize the matching of the resonant frequency, and/or the second capacitor C2 with a corresponding capacitance value and the second inductor L2 with a corresponding inductance value can be selected to realize the matching of the resonant frequency.

In a specific implementation, the first capacitor C1 may be an adjustable capacitor adjustable on chip, and the broadband performance of the rf power amplifier can be further improved by adjusting the capacitance value of the first capacitor C1.

Correspondingly, the second capacitor C2 may also be an on-chip adjustable capacitor, and the broadband performance of the rf power amplifier can be further improved by adjusting the capacitance value of the second capacitor C2.

In fig. 1 and 2, the first sub-filter circuit has the same structure as the second sub-filter circuit, it is understood that the structure of the first sub-filter circuit may be different from that of the second sub-filter circuit, for example, the first sub-filter circuit includes only the first capacitor C1, the second sub-filter circuit includes the second capacitor C2 and the second inductor L2, and for example, the first sub-filter circuit includes the first capacitor C1 and the first inductor L1, and the second sub-filter circuit includes only the second capacitor C2.

In a specific implementation, the input matched filter circuit may further include a parasitic capacitor, and the parasitic capacitor may be coupled between the first output terminal of the power amplification unit and the second output terminal of the power amplification unit.

In a specific implementation, the output matched filter circuit may include a third sub-filter circuit, a first terminal of the third sub-filter circuit may be coupled to the second terminal of the auxiliary secondary coil 122, and a second terminal of the third sub-filter circuit may be grounded.

In an embodiment of the present invention, the third sub-filter circuit may include a third capacitor C3; a first terminal of the third capacitor C3 may be coupled to the second terminal of the auxiliary secondary winding 122 and a second terminal of the third capacitor C3 may be grounded.

In a specific implementation, the third sub-filter circuit may further include a third inductor L3, and the third inductor L3 may be connected in series between the second terminal of the third capacitor C3 and ground.

Referring to fig. 3, a circuit structure diagram of another rf power amplifier according to an embodiment of the present invention is shown, in comparison with fig. 2, the rf power amplifier provided in fig. 3 has a third inductor L3, and by adding the third inductor L3, the harmonic filtering performance of the rf power amplifier can be further improved.

In a specific implementation, the output matched filter circuit may further include a fourth sub-filter circuit. In the embodiment of the present invention, a first terminal of the fourth sub-filter circuit may be coupled to the second terminal of the main secondary coil 121, and a second terminal of the fourth sub-filter circuit may be coupled to the OUTPUT terminal OUTPUT of the rf power amplifier.

The fourth sub-filter circuit can be L C matched filter circuit, the L C matched filter circuit can be two-order matched filter circuit, and can also be multi-order matched filter circuit, when the L C matched filter circuit is two-order matched filter circuit, it can include a series inductance and a capacitance to ground, when the L C matched filter circuit is multi-order matched filter circuit, it can include two series inductances or more series inductances and a capacitance to ground, or more capacitances to ground, and the number of series inductances is more than 1 than the number of capacitances to ground.

In a specific implementation, when the L C matching circuit is a two-stage matched filter circuit, referring to fig. 4, a circuit structure diagram of a radio frequency power amplifier according to another embodiment of the present invention is shown.

In fig. 4, the L C matched filter circuit includes a fourth inductor L4 and a fourth capacitor C4, wherein a first terminal of the fourth inductor L4 is coupled to the second terminal of the main secondary winding 121, a second terminal of the fourth inductor L4 is coupled to the OUTPUT terminal OUTPUT of the rf power amplifier, a first terminal of the fourth capacitor C4 is coupled to a second terminal of the fourth inductor L4, and a second terminal of the fourth capacitor C4 is grounded.

Referring to fig. 5, a circuit structure diagram of a radio frequency power amplifier according to another embodiment of the present invention is shown.

Compared with fig. 4, in fig. 5, the L C matched filter circuit further includes a fifth inductor L5 and a sixth inductor L6, wherein the fifth inductor L5 is connected in series between the second end of the fourth capacitor C4 and the ground, and the sixth inductor L6 is connected in series between the first end of the fourth capacitor C4 and the OUTPUT terminal OUTPUT of the rf power amplifier.

Referring to fig. 6, a circuit structure diagram of a radio frequency power amplifier according to another embodiment of the present invention is shown.

Compared with fig. 5, the L C matched filter circuit may further include a fifth capacitor C5, a seventh inductor L7, and an eighth inductor L8, wherein a first terminal of the fifth capacitor C5 is coupled to a second terminal of the sixth inductor L6, a second terminal of the fifth capacitor C5 is coupled to a first terminal of the seventh inductor L7, a first terminal of the seventh inductor L7 is coupled to a second terminal of the fifth capacitor C5, a second terminal of the seventh inductor L7 is grounded, a first terminal of the eighth inductor L8 is coupled to a first terminal of the fifth capacitor C5, a second terminal of the eighth inductor L8 is coupled to the OUTPUT terminal OUTPUT of the rf power amplifier, and the seventh inductor L7 and the fifth capacitor C5 form a resonant circuit.

In a specific implementation, the radio frequency power amplifier may further include a driving circuit. The INPUT terminal of the driving circuit may receive an INPUT signal, the first output terminal of the driving circuit may output a first differential signal INPUT _ P, and the second output terminal of the driving circuit may output a second differential signal INPUT _ N. The driving circuit can perform differential operation on the input signals and drive the input signals, so that the driving capability of the input signals is improved.

Referring to fig. 7, a circuit structure diagram of a radio frequency power amplifier according to another embodiment of the present invention is shown. In fig. 7, a driving circuit is added.

It is understood that in fig. 1 to 6, the INPUT signal may be subjected to a differential process by the driving circuit to obtain the first differential signal INPUT _ P and the second differential signal INPUT _ N.

In a specific implementation, the matched filter circuit may further include a parasitic capacitance corresponding to the power combining transformer, where the parasitic capacitance corresponding to the power combining transformer includes a parasitic capacitance between the primary coil and the secondary coil, and the parasitic capacitance may participate in power combining and impedance conversion.

The broadband transformer applied to the high-integration radio frequency power amplifier is influenced by the implementation process, the k value is often smaller (the k value is smaller and can influence energy coupling, namely the signal conversion efficiency is lower), the influence of the parasitic inductance capacitance is larger (the smaller coil self inductance and the larger parasitic capacitance can additionally influence the input and output impedance of the transformer, the impedance needs to be adjusted by adding or adjusting the matching capacitance of input and output to adjust the impedance, and further the additional impedance conversion is generated), and the effective impedance change ratio and the converted impedance phase of the transformer can be influenced, and the energy transmission efficiency can also be reduced.

In the embodiment of the invention, the auxiliary secondary coil is added, so that the energy coupling path from input to output can be added on the premise of not influencing the primary coil and the main secondary coil, and the influence of a small coupling coefficient k value on impedance transformation is reduced. According to the parameters such as the k values of the primary coil and the main secondary coil, the proper size and the k value of the auxiliary secondary coil are selected, so that the impedance conversion working frequency range of the power synthesis transformer can be effectively improved, and the loss of the power synthesis transformer is reduced. In addition, the main secondary coil and the auxiliary secondary coil of the power synthesis transformer and the matching filter circuit are cooperatively designed, so that the broadband impedance transformation and the filtering performance of the radio frequency power amplifier can be further improved.

The embodiment of the invention also provides communication equipment comprising the radio frequency power amplifier provided by any one of the embodiments. Other modules, such as a baseband chip, an antenna circuit, and the like, may also exist in the communication device, and the other modules may all adopt modules existing in the prior art, which is not described in detail in the embodiments of the present invention.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.