阅读说明：本技术 一种互补型功率合成的功率放大器结构 (Complementary power synthesis power amplifier structure ) 是由 王政 何飞 谢倩 于 2019-11-27 设计创作，主要内容包括：本发明属于射频集成电路领域,具体提供一种互补型功率合成的功率放大器结构,用以解决现有采用电容补偿技术的功率放大器功耗大、效率低的问题。本发明结构有效利用N型功率放大器和P型功率放大器的互补特性,通过P型功率放大器进行电容补偿,有效保证功率放大器结构线性度；同时,采用变压器将P型功率放大器的输出信号和N型功率放大器的输出信号进行功率合成,保证P型功率放大器的能量没有被浪费掉,使得整个功率放大器的输出功率得到提升,效率也得到提高；另外,提出失配调节网络,解决N型功率放大器与P型功率放大器输出匹配阻抗不同的问题；综上,本发明结构能够在保证功率放大器线性度的同时,提高输出功率及效率。(The invention belongs to the field of radio frequency integrated circuits, and particularly provides a complementary power synthesis power amplifier structure which is used for solving the problems of high power consumption and low efficiency of the conventional power amplifier adopting a capacitance compensation technology. The structure of the invention effectively utilizes the complementary characteristics of the N-type power amplifier and the P-type power amplifier, and the P-type power amplifier is used for capacitance compensation, thereby effectively ensuring the structural linearity of the power amplifier; meanwhile, the transformer is adopted to carry out power synthesis on the output signal of the P-type power amplifier and the output signal of the N-type power amplifier, so that the energy of the P-type power amplifier is ensured not to be wasted, the output power of the whole power amplifier is improved, and the efficiency is also improved; in addition, a mismatch adjusting network is provided, and the problem that the output matching impedance of the N-type power amplifier is different from that of the P-type power amplifier is solved; in conclusion, the structure of the invention can ensure the linearity of the power amplifier and simultaneously improve the output power and efficiency.)

1. A complementary power combining power amplifier structure, comprising: the power amplifier circuit comprises an N-type power amplifier (101), a P-type power amplifier (102), a transformer (103), an output matching network (104) and a mismatch adjusting network (105); the input differential signals are respectively input to an N-type power amplifier (101) and a P-type power amplifier (102) for power amplification, and output differential signals of the N-type power amplifier and the P-type power amplifier are respectively obtained; after impedance matching is carried out on the differential signal output by the N-type power amplifier and the differential signal output by the P-type power amplifier through a mismatch adjusting network (105), power synthesis is carried out through a transformer (103), and finally the power is transmitted to load impedance through an output matching network (104); characterized in that the mismatch adjustment network (105) is formed by a capacitor C₁And a capacitor C₂Is formed of the capacitor C₁Is connected to the positive output terminal and the negative output terminal of the N-type power amplifier (101), respectively, and the capacitor C₂Are respectively connected with the positive output terminal and the negative output terminal of the P-type power amplifier (102).

2. The complementary power combining power amplifier structure of claim 1, wherein in said mismatch adjustment network, the capacitor C₁And a capacitor C₂The following relationship needs to be satisfied:

wherein Z is_nmosIs the output impedance of an N-type power amplifier, Z_pmosIs the output impedance of the P-type power amplifier, Z₂And ω -2 pi f and f are the input impedance of the transformer and the working frequency of the power amplifier.

Technical Field

The invention belongs to the field of radio frequency integrated circuits, relates to a power amplifier, and particularly relates to a complementary power synthesis power amplifier structure.

Background

Power amplifiers are commonly used in communication systems to power amplify radio frequency small signals; but due to some non-linear characteristics, the power amplifier can not linearly amplify signals under high power output; factors causing the non-linear characteristic of the power amplifier are particularly many, such as memory effect of the power amplifier caused by parasitic elements, thermal effect of parasitic resistance, and the like. Amplitude/phase distortion is used to express the nonlinear characteristic of the power amplifier; the amplitude distortion means: when the input power is increased, the power gain of the power amplifier cannot be kept at a fixed value, but is reduced along with the increase of the input power, so that the output power value of the power gain reduced by 1dB is the output 1dB compression point of the power amplifier, the working state of the power amplifier should not exceed the output 1dB compression point, and the power gain can be kept at a constant value; and the phase distortion means: at different input powers, the phase value of the output voltage of the power amplifier and the phase value of the input voltage cannot be maintained at a constant value, thereby generating phase distortion. Amplitude and phase distortion can cause signal points to shift on a constellation diagram, and large distortion can even cause information not to be correctly demodulated; thus, the improvement of the linearity of the power amplifier can be made from the improvement of the amplitude/phase distortion.

In modern communication systems, the linearity requirements of power amplifiers for high power peak-to-average ratio signals become particularly high. The research on the amplitude/phase distortion of the power amplifier is beneficial to improving the linearity of the power amplifier, and in the aspect of amplitude distortion, the amplitude distortion of the power amplifier can be reduced by controlling the output power of the power amplifier; in terms of phase distortion, the gate/base capacitance of the transistor of the power amplifier is a variable value at different input powers; for an N-type transistor, the grid/base capacitance can be increased along with the increase of the input voltage, so that the distortion of the phase becomes large; in the design of the power amplifier, since the P-type transistor has the opposite characteristic to the N-type transistor, the gate/base capacitance of the P-type transistor is reduced with the increase of the input voltage, so that the complementary characteristics of the P-type transistor and the N-type transistor can be utilized to reduce the phase distortion of the power amplifier.

The technology of utilizing a P-type transistor to compensate is generally called as a capacitance compensation technology, a power amplifier designed by utilizing an N-type transistor is called as an N-type power amplifier, and the gate/base of the transistor of the N-type power amplifier is connected with the P-type transistor in parallel, and the gate/base of the N-type transistor and the gate/base of the P-type transistor are connected together in parallel, so that the P-type transistor plays a role of a capacitor; such as the one adopted in the document "A Nonlinear Capacitance localization techniques and applications location to a CMOS Class AB Power Amplifier". However, this type of structure has a drawback: the transistors of the power amplifier are usually large in size, and in order to compensate the gate/base capacitance of the N-type transistor, a P-type transistor which is as large as the N-type transistor is needed, and in addition, an independent power supply is also needed to be additionally arranged on the P-type transistor; therefore, in order to obtain a good linearity, a large power consumption is generated in the P-type transistor portion, so that the power consumption of the entire power amplifier becomes large and the power addition efficiency becomes low.

Disclosure of Invention

The invention aims to provide a complementary power synthesis power amplifier aiming at the problems of high power consumption and low efficiency of the power amplifier adopting the capacitance compensation technology; the power amplifier structure is based on a capacitance supplement technology, and the output signals of the P-type power amplifier and the N-type power amplifier are subjected to power synthesis by adopting a transformer, so that the output power and the efficiency of the whole power amplifier are improved.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a complementary power combining power amplifier structure, comprising: an N-type power amplifier 101, a P-type power amplifier 102, a transformer 103, an output matching network 104 and a mismatch adjusting network 105; wherein a differential signal V is input_in+、V_in-Respectively input to an N-type power amplifier 101 and a P-type power amplifier 102 for power amplification to respectively obtain output differential signals V of the N-type power amplifier_outn+、V_outn-And P type power amplifier output differential signal V_outp+And V_outp-(ii) a The output differential signal V_outn+、V_outn-And V_outp+、V_outp-After impedance matching is performed by the mismatch adjusting network 105, power synthesis is performed by the transformer 103, and finally the power is transmitted to the load impedance R through the output matching network 104₀(ii) a Characterized in that the mismatch adjusting network 105 is formed by a capacitor C₁And a capacitor C₂Is formed of the capacitor C₁Is connected to the positive output terminal and the negative output terminal of the N-type power amplifier 101, respectively, and the capacitor C₂Are respectively connected to the positive output terminal and the negative output terminal of the P-type power amplifier 102.

Further, in the mismatch adjusting network, a capacitor C₁And a capacitor C₂The following relationship needs to be satisfied:

wherein Z is_nmosIs the output impedance of an N-type power amplifier, Z_pmosIs the output impedance of the P-type power amplifier, Z₂And ω -2 pi f and f are the input impedance of the transformer and the working frequency of the power amplifier.

The invention has the beneficial effects that:

the invention provides a complementary power synthesis power amplifier structure, which effectively utilizes the complementary characteristics of an N-type power amplifier and a P-type power amplifier, and carries out capacitance compensation through the P-type power amplifier, thereby effectively ensuring the structural linearity of the power amplifier; meanwhile, the transformer is adopted to carry out power synthesis on the output signal of the P-type power amplifier and the output signal of the N-type power amplifier, so that the energy of the P-type power amplifier is ensured not to be wasted, the output power of the whole power amplifier is improved, and the efficiency is also improved; in addition, the invention provides a mismatch adjusting network, which solves the problem that the output matching impedance of the N-type power amplifier is different from that of the P-type power amplifier; in conclusion, the structure of the invention can ensure the linearity of the power amplifier and simultaneously improve the output power and efficiency.

The mismatch adjusting network part solves the problem that the output matching impedance of the N-type power amplifier and the output matching impedance of the P-type power amplifier are different.

The implementation of the invention provides a method for utilizing power synthesis, an N-type power amplifier and a P-type power amplifier are used for power synthesis, and the performances of high efficiency and larger output power are realized on the basis of solving the linearity. And a mismatch adjustment technology is provided, and the problem of inconsistent output impedance matching of the N-type power amplifier and the P-type power amplifier during power synthesis is solved.

Drawings

Fig. 1 is a schematic diagram of a complementary power combining power amplifier according to the present invention.

Fig. 2 is a schematic structural diagram of a mismatch adjustment network according to the present invention.

Fig. 3 is a schematic diagram of the transformer impedance transformation according to the present invention.

Fig. 4 is a schematic diagram of an output matching network according to the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The problems of high power consumption and low efficiency when the linearity of an N-type power amplifier is improved by using a P-type transistor for capacitance compensation in the prior art are solved; the invention fully considers the energy consumed on the P-type transistor, and performs power coupling on the energy through the transformer and the output power of the N-type power amplifier, thereby realizing the purpose of obtaining large output power and ensuring higher efficiency while ensuring the linearity.

This embodiment provides a complementaryThe structure of a power amplifier with power combining mode, as shown in fig. 1, includes: an N-type power amplifier 101, a P-type power amplifier 102, a transformer 103, an output matching network 104 and a mismatch adjusting network 105; wherein the input differential signal is respectively input to the N-type power amplifier 101 and the P-type power amplifier 102, and the input differential signal V_in+And V_in-Respectively carrying out power amplification through an N-type power amplifier 101 and a P-type power amplifier 102 to respectively obtain output differential signals V_outn+、V_outn-And V_outp+、V_outp-(ii) a Output differential signal V_outn+、V_outn-And V_outp+、V_outp-After impedance matching is performed by the mismatch adjusting network 105, power synthesis is performed by the transformer 103, and finally the power is transmitted to the load impedance R by the output matching network₀。

Originally speaking from the work: because the grid/base electrode of the N-type transistor of the N-type power amplifier 101 is correspondingly connected with the grid/base electrode of the P-type transistor of the P-type power amplifier 102, the P-type power amplifier 102 can play a role in capacitance compensation for the N-type power amplifier 101, and therefore the linearity of the whole power amplifier is improved. When actually matching the impedance, the impedance to be matched by the N-type power amplifier 101 and the P-type power amplifier 102 is different, and the impedance value can be determined for different purposes: such as maximum output power, maximum efficiency, maximum 1dB output power compression point, and the specific case is not limited to these but includes these. In order to solve the problem that the impedances to be matched by the N-type power amplifier 101 and the P-type power amplifier 102 are different, the mismatch adjusting network 105 is adopted in the present invention, as shown in fig. 2, two impedances of the N-type power amplifier 101 and the P-type power amplifier 102 are respectively Z_nmos、Z_pmosThe method of regulation is to use two parallel capacitors C respectively₁And C₂Capacitor C₁Are respectively connected with the output positive terminal V of the N-type power amplifier 101_outn+And a negative terminal V_outn-Capacitor C₂Both ends of the first and second switches are respectively connected with the positive output end V of the P-type power amplifier_outp+And a negative terminal V_outp-. Since the primary coils of the transformer are of the same structure, the transformer is adjusted from mismatchThe input impedance of the node network 105 to the transformer 104 is the same, and the input impedance of the transformer part is Z₂(ii) a Therefore, in order to achieve impedance matching, the two capacitances then satisfy the following expressions (1) and (2), respectively:

wherein, ω is 2 pi f, f is the working frequency of the power amplifier;

load impedance R₀After passing through the output matching network 104 as shown in FIG. 4, the load impedance R is adjusted₀Is matched to Z₁Then passes through a transformer 103 as shown in FIG. 3, impedance Z₁Conversion to impedance Z₂。

In the complementary power synthesis power amplifier structure, the complementary characteristics of an N-type power amplifier and a P-type power amplifier are effectively utilized, and the P-type power amplifier is utilized for capacitance compensation, so that the structural linearity of the power amplifier is effectively ensured; meanwhile, the transformer 103 is adopted to carry out power synthesis on the output signal of the P-type power amplifier 102 and the output signal of the N-type power amplifier 101, the energy of the P-type power amplifier 102 is not wasted, the output power of the whole power amplifier is improved, and the efficiency is also improved; in addition, a mismatch adjusting network 105 is provided to solve the problem that the output matching impedance of the N-type power amplifier is different from that of the P-type power amplifier; in conclusion, the structure of the invention can ensure the linearity of the power amplifier and simultaneously ensure larger output power and higher efficiency.

While the invention has been described with reference to specific embodiments, any feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise; all of the disclosed features, or all of the method or process steps, may be combined in any combination, except mutually exclusive features and/or steps.