Microwave / millimeter wave B / J type power amplifier

Abstract

A microwave / millimeter wave B / J type power amplifier comprises a driving amplification and harmonic generation circuit and an amplification circuit, a radio frequency input signal RFin is input through the signal input end of the driving amplification and harmonic generation circuit, and the signal output end of the driving amplification and harmonic generation circuit is connected with the signal input end of the amplification circuit. The amplification circuit outputs the amplified radio frequency signal; according to the multi-stage power amplifier, fundamental wave signal amplification, harmonic wave generation and harmonic wave phase and amplitude control are carried out at the same time through the pre-stage driving amplifier of the multi-stage power amplifier, fundamental waves and harmonic waves are input into the main amplifier at the same time, and waveform control is achieved so as to improve the efficiency of the power amplifier; the phase difference and the amplitude proportion of the second harmonic and the fundamental wave are controlled through the driving amplifier, the efficiency of the B / J type power amplifier can be improved, the maximum efficiency can reach 95.2%, the normalized voltage peak value is reduced compared with a traditional B / J type power amplifier, and the B / J type power amplifier has the advantages of being simple in structure, greatly improving the efficiency, improving the circuit reliability, and being small in area and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of power amplifiers, and in particular to a microwave / millimeter wave B / J class power amplifier. Background Art

[0002] Modern wireless communications have a growing demand for high-efficiency, high-speed, low-cost, and highly integrated RF front-end applications, such as satellite communications and 5G communications, which puts forward an urgent need for high-output power, high-efficiency, and low-cost silicon-based microwave / millimeter-wave power amplifiers. However, high-output power (watt-level), high-efficiency, and broadband silicon-based microwave / millimeter-wave power amplifiers still pose great challenges.

[0003] The gate bias V of a conventional class B power amplifier g Equal to the threshold voltage V of the tube TH , the conduction angle is 180°, and the maximum output power is Among them, I DC It is the DC component of the drain current. Class B power amplifiers only consider the impact of the fundamental wave, and do not consider the impact of harmonics on the working state. At high frequencies, high-order harmonics generated by parasitic parameters may reduce their efficiency.

[0004] Since the traditional Class B power amplifier does not consider the impact of high-order harmonics on the working state of MOS tubes, it is difficult to achieve high efficiency at high frequencies. In order to achieve high-efficiency power amplification at high frequencies, a Class J power amplifier is designed. Through the high-order harmonic impedance control of the passive matching circuit, the drain voltage waveform is controlled and the efficiency is improved. The phase difference between the voltage and current of the Class J power amplifier is 45° / -45°.

[0005] The gate bias V of the class J power amplifier g Equal to the threshold voltage V of the tube TH , the drain resonant cavity presents low resistance at the second harmonic frequency, realizing the control of the drain voltage waveform. The traditional J-class power amplifier only controls the fundamental and higher harmonic matching of the passive load, and the peak efficiency is only 78.5%, the same as the ideal B-class power amplifier. When the fundamental power of the J-class power amplifier is consistent with that of the B-class power amplifier, the voltage peak will exceed 2V DD ,In silicon-based low-voltage processes, output power and bandwidth need to be sacrificed to ensure reliability.

[0006] The input signal of the existing harmonic injection power amplifier is divided into two paths through a power divider. One path is passed through a harmonic generator to generate higher harmonics, and then passes through a variable phase shifter, a variable attenuator, etc. to generate higher harmonics with adjustable phase and amplitude, and then synthesized with the power of the other signal, and outputs the signal through the amplifier. This technology uses an additional higher harmonic generation circuit and performs harmonic injection by synthesizing with the main power amplifier power to achieve waveform control and efficiency improvement, but the additional second harmonic generation circuit will increase the circuit area and power consumption, limiting efficiency improvement.

[0007] In "Theory and Design of High-Efficiency Broadband Class-B / J Power Amplifiers With Active Second Harmonic Injection," (IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 71, NO. 10, OCTOBER 2023), Liu et al. proposed a theory and design method for a high-efficiency broadband continuous class B / J power amplifier (PA) combined with active second harmonic injection technology. By injecting the second harmonic components generated by the auxiliary power amplifier, the optimal phase shift parameter α between the drain voltage and current can be appropriately selected to improve the efficiency and power of the traditional class B / J power amplifier, but because this technology uses an additional active second harmonic injection circuit, it will increase the circuit area and power consumption, limiting the efficiency improvement. Summary of the invention

[0008] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a microwave / millimeter wave B / J class power amplifier, which utilizes the pre-stage driving amplifier of the multi-stage power amplifier to simultaneously amplify the fundamental signal, generate harmonics, and control the harmonic phase and amplitude, simultaneously inputs the fundamental wave and the second harmonic to the main amplifier, and simultaneously shapes the voltage and current waveforms of the tube drain, thereby achieving higher power and efficiency.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A microwave / millimeter wave B / J class power amplifier comprises a driving amplification and harmonic generation circuit and an amplification circuit, wherein a radio frequency input signal RFin is input through a signal input end of the driving amplification and harmonic generation circuit, a signal output end of the driving amplification and harmonic generation circuit is connected to a signal input end of the amplification circuit, and the amplification circuit outputs an amplified radio frequency signal; the driving amplification and harmonic generation circuit is used for input matching and second harmonic generation; and the amplification circuit is used for further amplifying an output signal generated by the driving amplification and second harmonic generation circuit.

[0011] The driving amplification and harmonic generation circuit includes an input matching and harmonic generation circuit, a driving amplification and harmonic phase / amplitude control circuit; the amplification circuit includes a main amplifier and an output matching circuit; wherein the radio frequency input signal RFin is input through the input end of the input matching and harmonic generation circuit, the radio frequency signal output end of the input matching and harmonic generation circuit is connected to the radio frequency signal input end of the driving amplification and harmonic phase / amplitude control circuit, the signal output end of the driving amplification and harmonic phase / amplitude control circuit is connected to the signal input end of the main amplifier, the signal output end of the main amplifier is connected to the output matching circuit, and the output matching circuit outputs the radio frequency signal RFout.

[0012] The input matching and harmonic generation circuit includes a first transformer T1. The radio frequency signal input terminal RFin is connected to the signal input terminal of the first transformer T1. The first transformer T1 performs input matching and single-ended signal conversion to differential, and generates second harmonics using the asymmetry of the transformer.

[0013] The driving amplifier and harmonic phase / amplitude control circuit includes a driving amplifier and a second transformer T2, which are used to complete fundamental and second harmonic amplification and fundamental and second harmonic phase / amplitude control; wherein the signal output end of the driving amplifier is connected to the signal input end of the second transformer T2.

[0014] The drain current of the MOS tube of the main amplifier is:

[0015]

[0016] Among them, I1 and I2 are the maximum currents generated by the fundamental wave and the second harmonic at the drain respectively.

[0017] The drain voltage of the MOS tube of the main amplifier is:

[0018] v d =(V DD -V th )(1-coswt)(1-αsinwt)=(V DD -V th )×(1-coswt-αsinwt+αsinwtcoswt)

[0019] Among them, V DD is the DC voltage of the MOS tube drain, V th is the MOS tube threshold voltage, and α is the design parameter.

[0020] From the above formula, we can calculate the fundamental impedance and second harmonic impedance required by the output matching circuit:

[0021]

[0022] At the same time, according to the above drain current and voltage expressions, the DC power consumption of the microwave / millimeter wave B / J class power amplifier is:

[0023]

[0024] Among them, I1 is the maximum current generated by the fundamental wave at the drain, V DD is the DC voltage of the MOS tube drain, V th is the MOS tube threshold voltage.

[0025] The fundamental wave power of the microwave / millimeter wave B / J class power amplifier is:

[0026]

[0027] The drain efficiency of the microwave / millimeter wave class B / J power amplifier can be calculated based on the DC power consumption and fundamental wave power:

[0028]

[0029] I1 and I2 satisfy: That is, the conduction angle is 180°.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention utilizes the pre-stage driving amplifier of the multi-stage power amplifier, namely the driving amplifier and the harmonic generator to simultaneously amplify the fundamental signal, generate harmonics, and control the harmonic phase and amplitude, and simultaneously inputs the fundamental and harmonics into the main amplifier to realize waveform control to improve the efficiency of the power amplifier.

[0032] 2. By adjusting the output matching circuit of the main amplifier, the present invention can adjust the matching circuit and the resonant cavity circuit according to the second harmonic component in the input signal.

[0033] 3. The present invention uses the asymmetry of the input matching circuit of the driving amplifier to generate second harmonics, which are used together with the amplified baseband signal as the input signal of the main power amplifier; or uses the nonlinearity of the active circuit of the driving amplifier to generate second harmonics, which are used together with the amplified baseband signal as the input signal of the main power amplifier; or uses other methods to make the driving amplifier generate second harmonics, which are used together with the amplified baseband signal as the input signal of the main power amplifier; it has the advantages and innovations of simple circuit architecture, no need for additional hardware overhead, high efficiency and small area.

[0034] 4. The present invention controls the phase difference and amplitude ratio between the second harmonic and the fundamental wave by driving the amplifier, thereby improving the efficiency of the B / J class power amplifier, and the maximum efficiency can reach 95.2%.

[0035] 5. The present invention adjusts the phase relationship between the fundamental wave and the second harmonic. When the phase difference between the fundamental wave and the second harmonic is 90°, the voltage peak value can be reduced, thereby increasing the output power and bandwidth of the power amplifier and improving reliability.

[0036] 6. The present invention utilizes the original circuit structure of a multi-stage cascade power amplifier, without any additional hardware overhead and power consumption.

[0037] In summary, the present invention utilizes the pre-stage driving amplifier of the multi-stage power amplifier to simultaneously amplify the fundamental signal, generate harmonics, and control the harmonic phase and amplitude, simultaneously inputs the fundamental and second harmonics to the main amplifier, and simultaneously shapes the voltage and current waveforms of the tube drain, without the need for an additional active second harmonic injection circuit, thereby achieving higher power and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural principle diagram of the present invention.

[0039] Figure 2 It is a schematic structural diagram of an embodiment of the present invention.

[0040] Figure 3 It is a comparison chart of the reliability improvement of the present invention compared with the traditional B / J class power amplifier; among them, (a) is the reliability improvement chart of the traditional B / J class power amplifier; (b) is the reliability improvement chart of the present invention. DETAILED DESCRIPTION

[0041] In order to more clearly illustrate the technical solution and advantages of the present invention, the present invention is described in detail below in combination with specific implementation steps. It should be noted that the implementation steps described below are only used to explain the present invention, rather than to limit the present invention.

[0042] See also Figure 1 A microwave / millimeter wave B / J class power amplifier comprises a driving amplifier and harmonic generation circuit and an amplifier circuit, wherein a radio frequency input signal RFin is input through a signal input terminal of the driving amplifier and harmonic generation circuit, a signal output terminal of the driving amplifier and harmonic generation circuit is connected to a signal input terminal of the amplifier circuit, and the amplifier circuit outputs an amplified radio frequency signal; the driving amplifier and harmonic generation circuit are used for input matching and second harmonic generation of the power amplifier, that is, Figure 1 The RF output drv The amplifier circuit is used to further amplify and output the output signal generated by the drive amplifier and the second harmonic generation circuit, that is, Figure 1 The RF signal RFout outputted from.

[0043] See also Figure 2 , Figure 2This is an embodiment of the present invention. A microwave / millimeter wave B / J class power amplifier described in this embodiment includes a driving amplifier and harmonic generation circuit and an amplifier circuit; the driving amplifier and harmonic generation circuit includes an input matching and harmonic generation circuit, a driving amplifier and harmonic phase / amplitude control circuit; the amplifier circuit includes a main amplifier and an output matching circuit, wherein the radio frequency input signal RFin is connected to the input end of the input matching and harmonic generation circuit, the radio frequency signal output end of the input matching and harmonic generation circuit is connected to the radio frequency signal input end of the driving amplifier and harmonic phase / amplitude control circuit, the signal output end of the driving amplifier and harmonic phase / amplitude control circuit is connected to the main amplifier, the output end of the main amplifier is connected to the output matching circuit, and the output matching circuit outputs the radio frequency signal RFout.

[0044] The input matching and harmonic generation circuit includes a first transformer T1, the radio frequency input signal RFin is connected to the signal input end of the first transformer T1, the output end of the first transformer T1 is connected to the input end of the driving amplifier, and the positive end and the negative end of the first transformer T1 are respectively connected to the positive end and the negative end of the driving amplifier; the first transformer T1 performs input matching and single-ended signal differential conversion, and uses the asymmetry of the first transformer T1 to generate secondary harmonics.

[0045] The driving amplifier and harmonic phase / amplitude control circuit is used to complete fundamental and second harmonic amplification, fundamental and second harmonic phase / amplitude control, and specifically includes a driving amplifier and a second transformer T2. The positive end and negative end of the driving amplifier output are respectively connected to the positive end and negative end of the second transformer T2 input, and the positive end and negative end of the second transformer T2 output are respectively connected to the positive end and negative end of the main amplifier input.

[0046] The amplifier circuit performs waveform shaping and class J power amplification, and specifically includes a main amplifier and an output match, wherein the positive end and the negative end of the main amplifier are respectively connected to the positive end and the negative end of the output match; the output match outputs a radio frequency signal RFout.

[0047] In this embodiment, a transformer is used for input matching, the first transformer T1 uses a transformer with a primary coil and a secondary coil coupled, the driving amplifier uses a common source and common gate circuit, the second transformer T2 uses a transformer with a primary coil and a secondary coil coupled, the main amplifier uses a common source and common gate circuit, and the output matching uses a transformer with a primary coil and a secondary coil coupled and a matching capacitor.

[0048] When the signal is input, the non-ideal characteristics of the input passive matching circuit of the driving amplifier are used to generate a differential second harmonic signal. The fundamental and second harmonic signals are amplified by the driving amplifier and the phase relationship between the fundamental and second harmonic is adjusted to make the phase difference 90°, thereby finally achieving high-efficiency power output, reducing voltage peak and improving reliability.

[0049] like Figure 3 As shown, the normalized voltage value of the B / J class power amplifier of the present invention is less than 1.5 times VDD, which reduces the voltage peak value compared with the traditional B / J class power amplifier; when the fundamental power of the J class power amplifier of the present invention is consistent with that of the B class power amplifier, the voltage peak value of the drain will not exceed 2V DD , thereby improving the reliability, maximum output power and available operating bandwidth of the power amplifier.

[0050] The class B / J power amplifier of the present invention utilizes the original circuit structure of a multi-stage cascade power amplifier, has no additional hardware overhead and power consumption, and has a smaller circuit area and higher efficiency than a traditional harmonic injection amplifier.

[0051] The B / J class power amplifier of the present invention has a theoretical maximum efficiency increased by 16.7% to 95.2% compared to the traditional B / J class power amplifier. The normalized voltage value of the B / J class power amplifier of the present invention is less than 1.5 times VDD, and the voltage peak is reduced compared to the traditional B / J class, thereby improving the reliability, maximum output power and available working bandwidth of the power amplifier, without additional hardware overhead and power consumption, and having a smaller circuit area and higher efficiency than the traditional harmonic injection amplifier.

Claims

1. A microwave / millimeter wave class B / J power amplifier, characterized in that: It comprises a driving amplification and harmonic generation circuit and an amplification circuit, wherein a radio frequency input signal RFin is input through a signal input end of the driving amplification and harmonic generation circuit, a signal output end of the driving amplification and harmonic generation circuit is connected to a signal input end of the amplification circuit, and the amplification circuit outputs an amplified radio frequency signal; the driving amplification and harmonic generation circuit is used for input matching and second harmonic generation; and the amplification circuit is used for further amplifying the output signal generated by the driving amplification and second harmonic generation circuit.

2. A microwave / millimeter wave class B / J power amplifier according to claim 1, characterized in that: The driving amplification and harmonic generation circuit includes an input matching and harmonic generation circuit, a driving amplification and harmonic phase / amplitude control circuit; the amplification circuit includes a main amplifier and an output matching circuit; wherein the radio frequency input signal RFin is input through the input end of the input matching and harmonic generation circuit, the radio frequency signal output end of the input matching and harmonic generation circuit is connected to the radio frequency signal input end of the driving amplification and harmonic phase / amplitude control circuit, the signal output end of the driving amplification and harmonic phase / amplitude control circuit is connected to the signal input end of the main amplifier, the signal output end of the main amplifier is connected to the output matching circuit, and the output matching circuit outputs the radio frequency signal RFout.

3. A microwave / millimeter wave class B / J power amplifier according to claim 2, characterized in that: The input matching and harmonic generation circuit includes a first transformer T1. The radio frequency signal input terminal RFin is connected to the signal input terminal of the first transformer T1. The first transformer T1 performs input matching and single-ended signal conversion to differential, and generates second harmonics using the asymmetry of the transformer.

4. The microwave / millimeter wave class B / J power amplifier according to claim 2, characterized in that: The driving amplifier and harmonic phase / amplitude control circuit includes a driving amplifier and a second transformer T2, which are used to complete fundamental and second harmonic amplification and fundamental and second harmonic phase / amplitude control; wherein the signal output end of the driving amplifier is connected to the signal input end of the second transformer T2.

5. The microwave / millimeter wave class B / J power amplifier according to claim 1, characterized in that: The drain current of the MOS tube of the main amplifier is: Among them, I1 and I2 are the maximum currents generated by the fundamental wave and the second harmonic at the drain respectively. The drain voltage of the MOS tube is: v d =(V DD -V th )(1-cos wt)(1-αsin wt)=(V DD -V th )×(1-cos wt-αsin wt+αsin wt coswt) Among them, V DD is the DC voltage of the MOS tube drain, V th is the MOS tube threshold voltage, and α is the design parameter.

6. The microwave / millimeter wave class B / J power amplifier according to claim 1, characterized in that: The fundamental impedance and second harmonic impedance required by the output matching circuit are:

7. The microwave / millimeter wave class B / J power amplifier according to claim 1, characterized in that: The DC power consumption of the microwave / millimeter wave class B / J power amplifier is: Among them, l1 is the maximum current generated by the fundamental wave at the drain, V DD is the DC voltage of the MOS tube drain, V th is the MOS tube threshold voltage; The fundamental wave power of the microwave / millimeter wave B / J class power amplifier is: The drain efficiency of the microwave / millimeter wave class B / J power amplifier can be calculated based on the DC power consumption and fundamental wave power:

8. The microwave / millimeter wave class B / J power amplifier according to claim 7, characterized in that: I1 and I2 satisfy: That is, the conduction angle is 180°, and the phase difference between the amplifier fundamental and second harmonic is 90°.

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