Generalized parallel EF type power amplifier based on output end active third harmonic injection

Abstract

The invention discloses a generalized parallel EF type power amplifier based on output end active third harmonic injection, a main power amplifier is connected with an auxiliary power amplifier through an inductance-capacitance third harmonic resonance circuit, and a second reactor is arranged between the inductance-capacitance third harmonic resonance circuit and the auxiliary power amplifier; a drain electrode of the main power amplifier transistor is connected with a main power amplifier drain electrode power supply through a lambda / 4 transmission line; one end of the main switch is respectively connected with one end of the first capacitor, one end of the first inductor, one end of the lambda / 4 transmission line, one end of the inductance-capacitance third harmonic resonance circuit and one end of the inductance-capacitance resonance circuit; the other end of the lambda / 4 transmission line is connected with a main power amplifier drain electrode power supply; the other end of the inductance-capacitance resonance circuit is connected with one end of an output end load; a first reactor is arranged between the other end of the inductance-capacitance resonance circuit and one end of the output end load; the other end of the main switch is respectively connected with the other end of the first capacitor, the other end of the first ideal blocking capacitor and the other end of the output end load; the first reactance and the second reactance are variable reactance.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication power amplifiers, and particularly relates to a generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end. Background Art

[0002] With the rapid development of wireless communication technology, the research and development of related components of wireless communication systems are facing huge challenges. The power amplifier is one of the essential modules in the transmitter part of a wireless communication system. Its main function is to amplify the modulated signal to meet the power requirements for antenna radiation. The performance of the power amplifier directly determines the quality of the wireless communication system. Therefore, the indicators of high efficiency, wide bandwidth, high power, and high linearity have increasingly become the focus of attention. The power amplifier is the most energy-consuming module in the entire wireless communication system. If the working efficiency of the power amplifier is improved, the power consumption of the entire system can be reduced. Therefore, improving the efficiency of the power amplifier is of crucial significance.

[0003] Currently, there are mainly two types of high-efficiency power amplifiers: switching power amplifiers (with class-E power amplifiers being the most typical) and harmonic-tuned power amplifiers (with class-F power amplifiers being the most typical). Switching power amplifiers have high efficiency, simple structures, and are easy to implement. However, they have disadvantages such as low carrier frequency and high drain peak voltage. The broadband high-efficiency EF-class power amplifier with a parallel circuit combines the advantages of single-mode class-E and class-F power amplifiers through circuit hybridization, significantly improving the peak drain voltage, maximum operating frequency, and power output ability of the power amplifier. However, there is still the problem of current discontinuity during the transition of the transistor from the on state to the off state, resulting in a serious decline in the actual working efficiency under non-ideal conditions.

[0004] Therefore, it is currently necessary to solve the problem of a serious decline in efficiency caused by sudden changes in the drain circuit of the existing broadband high-efficiency EF-class power amplifier with a parallel circuit under non-ideal conditions. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problem of a serious decline in efficiency caused by sudden changes in the drain circuit of the existing broadband high-efficiency EF-class power amplifier with a parallel circuit under non-ideal conditions, and a generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end is proposed.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end, including a main power amplifier and an auxiliary power amplifier. The main power amplifier includes a main switch, a first capacitor, a first inductor, a first ideal DC-blocking capacitor, λ / 4 transmission line, main power amplifier drain power supply, inductance-capacitance third harmonic resonance circuit and inductance-capacitance resonance circuit, λ is the wavelength; The main power amplifier is connected to the auxiliary power amplifier through the inductance-capacitance third harmonic resonance circuit, and a second reactance is provided between the inductance-capacitance third harmonic resonance circuit and the auxiliary power amplifier; The main switch is the main power amplifier transistor, and the drain of the main power amplifier transistor is connected to the main power amplifier drain power supply through λ the / 4 transmission line; One end of the main switch is respectively connected to one end of the first capacitor, one end of the first inductor, λ one end of the / 4 transmission line, one end of the inductance-capacitance third harmonic resonance circuit and one end of the inductance-capacitance resonance circuit; The other end of the first inductor is connected to one end of the first ideal DC-blocking capacitor, λ the other end of the / 4 transmission line is connected to the main power amplifier drain power supply, and the other end of the inductance-capacitance resonance circuit is connected to one end of the output load; a first reactance is provided between the other end of the inductance-capacitance resonance circuit and one end of the output load; The other end of the main switch is respectively connected to the other end of the first capacitor, the other end of the first ideal DC-blocking capacitor and the other end of the output load; The first reactance and the second reactance are variable reactances.

[0007] Further, the auxiliary power amplifier includes an auxiliary switch, a second capacitor, a second inductor, a second ideal DC-blocking capacitor and an RFC; One end of the auxiliary switch is respectively connected to one end of the second capacitor, one end of the second inductor, one end of the RFC and one end of the second reactance; The other end of the second inductor is connected to one end of the second ideal DC-blocking capacitor, and the other end of the RFC is connected to the auxiliary power amplifier drain power supply; The other end of the auxiliary switch is respectively connected to the other end of the second capacitor and the other end of the second ideal DC-blocking capacitor; The auxiliary switch is an auxiliary power amplifier transistor, and the drain of the auxiliary power amplifier transistor is connected to the auxiliary power amplifier drain power supply through the RFC.

[0008] Further, the inductance-capacitance third harmonic resonance circuit includes a third capacitor and a third inductor, one end of the third capacitor is connected to one end of the main switch, the other end of the third capacitor is connected to one end of the third inductor, and the other end of the third inductor is connected to one end of the second reactance; the other end of the second reactance is connected to one end of the auxiliary switch; The inductance-capacitance resonance circuit includes a fourth capacitor and a fourth inductor, one end of the fourth inductor is connected to one end of the main switch, the other end of the fourth inductor is connected to one end of the fourth capacitor, the other end of the fourth capacitor is connected to one end of the first reactance, and the other end of the first reactance is connected to one end of the output load.

[0009] In a second aspect, the present invention provides a design method for a generalized parallel class - EF power amplifier based on active third - harmonic injection at the output end. Using the generalized parallel class - EF power amplifier based on active third - harmonic injection at the output end, the method includes the following steps: Both the main power amplifier and the auxiliary power amplifier are in a switching - type mode. The main power amplifier forms a parallel EF mode through a λ / 4 transmission line and a first inductor; the auxiliary power amplifier operates at the third - harmonic frequency, and the harmonics generated by the auxiliary power amplifier are injected into the output end of the main power amplifier through an inductor - capacitor third - harmonic resonance circuit; a first reactance is connected in series in the main power amplifier to introduce a first key factor, and a second reactance is connected in series in the auxiliary power amplifier to introduce a second key factor; By changing the first key factor, the second key factor, and the stagnation radian at the unit angular frequency of the input signal, calculate the drain voltage and drain current waveforms of the main power amplifier and the auxiliary power amplifier in each operating state, and derive a number of impedance solutions to form an impedance space of a switching - type hybrid generalized parallel class - EF power amplifier based on active third - harmonic injection at the output end.

[0010] Furthermore, λ The period of the current in the λ / 4 transmission line is , and the switching states of the main - power - amplifier transistor include a first stage, a second stage, a third stage, and a fourth stage; When the switching state of the main - power - amplifier transistor is in the first stage, it is in a closed state, and the phase is in the range from 0 to ; When the switching state of the main - power - amplifier transistor is in the first stage, the current expression of the main switch is:

[0011] Wherein, is the main - switch current in the first stage, is the simplified main - switch current in the first stage, is the initial phase of the current flowing through the load resistor, is the phase, is the initial phase of the third - harmonic injection current, V dd1 is the drain - supply voltage of the main power amplifier, p is the first parameter of the main power amplifier, r 1 is the second parameter of the main power amplifier; When the switching state of the main - power - amplifier transistor is in the second stage, it is in an open state, and the phase is in the range from to ; When the switching state of the main - power - amplifier transistor is in the second stage, the expression of the second - order linear non - homogeneous differential equation of the main - switch voltage is:

[0012] Among them, p is the first parameter of the main power amplifier, r 1 is the second parameter of the main power amplifier, k 1 is the first key factor, is the voltage across the capacitor at the second stage; When the switching state of the main power amplifier transistor is in the second stage, the normalized general solution of the second-order linear non-homogeneous differential equation of the main switch voltage is:

[0013] When the switching state of the main power amplifier transistor is in the third stage, it is in the off state, and the phase is in to range; When the switching state of the main power amplifier transistor is in the third stage, the voltage expression of the main switch is:

[0014] Among them, is the voltage across the capacitor at the third stage; When the switching state of the main power amplifier transistor is in the fourth stage, it is in the off state, and the phase is in to range; When the switching state of the main power amplifier transistor is in the fourth stage, the voltage expression of the main power amplifier is:

[0015] Among them, is the voltage across the capacitor at the fourth stage; The is the stagnation radian at the unit angular frequency of the input signal. The relationship expression between the stagnation radian at the unit angular frequency of the input signal and the duty cycle of the gate signal is:

[0016] Among them, D is the duty cycle of the gate signal, is the stagnation radian at the unit angular frequency of the input signal; The load impedance is expressed by using the fundamental frequency orthogonal component of the switching voltage and the output power. The first inductor is expressed by using the first parameter. The first capacitor is expressed by using the first parameter and the first key factor. The first reactance is expressed by using the fundamental frequency orthogonal component of the main power amplifier switching voltage. The third harmonic injection current of the main power amplifier is expressed by using the second parameter.

[0017] Furthermore, the expression of the load impedance is:

[0018] Among them, R is the load impedance, V Ris the fundamental frequency quadrature resistance component of the switching voltage, P out is the output power; The expression of the first inductor is:

[0019] wherein, L 1 is the first inductor, p is the first parameter of the main power amplifier, V dd1 is the drain supply voltage of the main power amplifier, The expression of the first capacitor is:

[0020] wherein, C 1 is the first capacitor, k 1 is the first key factor; The expression of the first reactance is:

[0021] wherein, X 1 is the first reactance, V X1 is the fundamental frequency quadrature reactance component of the switching voltage of the main power amplifier; The expression of the third harmonic injection current of the main power amplifier is:

[0022] wherein, is the third harmonic injection current of the main power amplifier, p is the first parameter of the main power amplifier, r 1 is the second parameter of the main power amplifier.

[0023] Furthermore, the inductor-capacitor third harmonic resonance circuit behaves as a short circuit at the third harmonic and as an open circuit at other harmonics; The λ / 4 transmission line is short-circuited at even harmonics and open-circuited at odd harmonics; The peak value of the drain voltage of the main power amplifier transistor is controlled to be twice the drain supply voltage.

[0024] Furthermore, the operating frequency of the auxiliary power amplifier is three times the operating frequency of the main power amplifier, and the switching state of the auxiliary power amplifier transistor includes a first stage and a second stage; When the switching state of the auxiliary power amplifier transistor is in the first stage, it is in the closed state, and the phase is within 0 to range; When the switching state of the auxiliary power amplifier transistor is in the first stage, the current expression of the auxiliary switch is:

[0025] Among them, is the current of the first stage of the auxiliary switch, is the simplified current of the first stage of the auxiliary switch, is the phase, L 2 is the second inductor, V dd1 is the drain supply voltage of the main power amplifier, is the first parameter of the auxiliary power amplifier, r 2 is the second parameter of the auxiliary power amplifier, is the initial phase of the third harmonic injection current; When the switching state of the auxiliary power amplifier transistor is in the second stage, it is in the off state, and the phase is in to range; When the switching state of the auxiliary power amplifier transistor is in the second stage, the second-order linear non-homogeneous differential equation of the voltage of the auxiliary switch is:

[0026] Among them, k 2 is the second key factor, is the voltage across the second capacitor; When the switching state of the auxiliary power amplifier transistor is in the second stage, the normalized general solution of the second-order linear non-homogeneous differential equation of the voltage of the auxiliary switch is: ; The second inductor is expressed by using the first parameter of the main power amplifier, the second parameter of the main power amplifier, and the second parameter of the auxiliary power amplifier; the second capacitor is expressed by using the first parameter of the main power amplifier, the second parameter of the main power amplifier, the second parameter of the auxiliary power amplifier, and the third parameter of the auxiliary power amplifier; the second reactance is expressed by using the first parameter of the main power amplifier and the second parameter of the main power amplifier; the load circuit of the auxiliary power amplifier is equivalent to the third harmonic equivalent resistance of the main power amplifier and the third harmonic equivalent reactance of the main power amplifier, and the third harmonic equivalent resistance of the main power amplifier and the third harmonic equivalent reactance of the main power amplifier are expressed by using the first parameter of the main power amplifier and the second parameter of the main power amplifier.

[0027] Furthermore, the expression of the second inductor is:

[0028] Among them, L 2 is the second inductor, p is the first parameter of the main power amplifier, r 2 is the second parameter of the auxiliary power amplifier, V R is the orthogonal resistance component of the fundamental frequency of the switching voltage, V dd1 is the drain supply voltage of the main power amplifier, r 1 is the second parameter of the main power amplifier,P out is the output power; The expression of the second capacitor is: ; Wherein, C 2 is the second capacitor, k 2 is the second key factor; The expression of the second reactance is:

[0029] Wherein, X 2 is the second reactance, V S2b is the second orthogonal component of the third harmonic of the auxiliary power amplifier switching voltage, is the third harmonic injection current of the main power amplifier, V Xinj is the orthogonal reactance component of the main power amplifier switching voltage at the third harmonic; The expression of the main power amplifier third harmonic equivalent resistance is:

[0030] Wherein, R inj is the main power amplifier third harmonic equivalent resistance, V Rinj is the orthogonal resistance component of the main power amplifier switching voltage at the third harmonic; The expression of the main power amplifier third harmonic equivalent reactance is:

[0031] Wherein, X inj is the main power amplifier third harmonic equivalent reactance.

[0032] A transmitter, including the generalized parallel class EF power amplifier based on active third harmonic injection at the output end described above.

[0033] Compared with the prior art, the present invention has the following beneficial technical effects: The generalized parallel class-EF power amplifier based on active third-harmonic injection at the output end proposed by the present invention introduces an auxiliary power amplifier. Active third-harmonic injection is carried out at the drain of the transistor of the broadband high-efficiency class-EF power amplifier with a parallel circuit, so that the main power amplifier satisfies both the ZVS and ZVDS conditions and the ZCS and ZCDS conditions, thereby eliminating the current discontinuity during the transition of the transistor from the on state to the off state, and thus improving the actual working efficiency in a non-ideal environment. The variable reactance elements X1 and X2 add two additional degrees of freedom to the circuit. The series pure reactance element X1 introduces a key factor k1 to the main power amplifier, and the series pure reactance element X2 introduces a key factor k2 to the auxiliary power amplifier. By changing k1, k2 and the stagnation angle τ d , a number of impedance solutions can be derived, thus expanding the impedance design space. Description of the Drawings

[0034] The schematic diagrams in the specification are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0035] Figure 1 It is the circuit structure schematic diagram of the generalized parallel class-EF power amplifier based on active third-harmonic injection at the output end of the present invention.

[0036] Figure 2 It is the equivalent schematic diagram of the main power amplifier of the generalized parallel class-EF power amplifier based on active third-harmonic injection at the output end of the present invention.

[0037] Figure 3 It is the equivalent schematic diagram of the auxiliary power amplifier of the generalized parallel class-EF power amplifier based on active third-harmonic injection at the output end of the present invention.

[0038] Figure 4a In the embodiment of the present invention, at the specified , , , the normalized drain voltage waveforms and current waveforms of the main power amplifier in ideal calculation and simulation verification are respectively shown.

[0039] Figure 4b In the embodiment of the present invention, at the specified , , , the normalized drain voltage waveforms and current waveforms of the auxiliary power amplifier in ideal calculation and simulation verification are respectively shown. Detailed Embodiments

[0040] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0042] Embodiment 1 See Figure 1 , a generalized parallel class EF power amplifier based on active third-harmonic injection at the output end A generalized parallel class EF power amplifier based on active third-harmonic injection at the output end includes a main power amplifier and an auxiliary power amplifier. The main power amplifier includes a main switch, a first capacitor, a first inductor, a first ideal DC-blocking capacitor, λ a λ / 4 transmission line, a main power amplifier drain power supply, an inductor-capacitor third-harmonic resonance circuit, and an inductor-capacitor resonance circuit, λ where λ is the wavelength; The main power amplifier is connected to the auxiliary power amplifier through the inductor-capacitor third-harmonic resonance circuit, and a second reactance X2 is provided between the inductor-capacitor third-harmonic resonance circuit and the auxiliary power amplifier. The main switch is a main power amplifier transistor, and the drain of the main power amplifier transistor is connected to the main power amplifier drain power supply through λ a λ / 4 transmission line; one end of the main switch is respectively connected to one end of the first capacitor, one end of the first inductor, λ one end of the λ / 4 transmission line, one end of the inductor-capacitor third-harmonic resonance circuit, and one end of the inductor-capacitor resonance circuit; the other end of the first inductor is connected to one end of the first ideal DC-blocking capacitor, λ the other end of the λ / 4 transmission line is connected to the main power amplifier drain power supply, and the other end of the inductor-capacitor resonance circuit is connected to the output load R LOne end; a first reactance X1 is provided between the other end of the inductance-capacitance resonant circuit and one end of the output load; the other end of the main switch is respectively connected to the other end of the first capacitor, the other end of the first ideal DC-blocking capacitor, and the other end of the output load; the first reactance and the second reactance are variable reactances.

[0043] The inductance-capacitance third-harmonic resonant circuit includes a third capacitor and a third inductor. One end of the third capacitor is connected to one end of the main switch, the other end of the third capacitor is connected to one end of the third inductor, and the other end of the third inductor is connected to one end of the second reactance; the other end of the second reactance is connected to one end of the auxiliary switch; the inductance-capacitance resonant circuit includes a fourth capacitor and a fourth inductor. One end of the fourth inductor is connected to one end of the main switch, the other end of the fourth inductor is connected to one end of the fourth capacitor, the other end of the fourth capacitor is connected to one end of the first reactance, and the other end of the first reactance is connected to one end of the output load.

[0044] The auxiliary power amplifier includes an auxiliary switch, a second capacitor, a second inductor, a second ideal DC-blocking capacitor, and an RFC (radiofrequency choke); one end of the auxiliary switch is respectively connected to one end of the second capacitor, one end of the second inductor, one end of the RFC, and one end of the second reactance; the other end of the second inductor is connected to one end of the second ideal DC-blocking capacitor, and the other end of the RFC is connected to the auxiliary power amplifier drain power supply; the other end of the auxiliary switch is respectively connected to the other end of the second capacitor and the other end of the second ideal DC-blocking capacitor; the auxiliary switch is an auxiliary power amplifier transistor, and the drain of the auxiliary power amplifier transistor is connected to the auxiliary power amplifier drain power supply through the RFC.

[0045] Embodiment 2 A transmitter includes the generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end described in Embodiment 1.

[0046] Embodiment 3 A design method of the generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end, using the generalized parallel EF-class power amplifier based on active third-harmonic injection at the output end described in Embodiment 1, includes the following steps: Both the main power amplifier and the auxiliary power amplifier are in the switching mode. The parallel capacitors C1 (i.e., the first capacitor) and C2 (i.e., the second capacitor) complete the charging and discharging during the on and off states of the transistors. The main power amplifier forms a parallel EF mode through a λ / 4 transmission line (λ represents the wavelength at the operating frequency) and a parallel inductor L1 (i.e., the first inductor). The auxiliary power amplifier operating at the third harmonic injects the harmonics it generates into the output terminal of the main power amplifier. The variable reactance elements X1 and X2 add two additional degrees of freedom k1 and k2 to the circuit. The series pure reactance element X1 introduces the key factor k1 to the main power amplifier, and the series pure reactance element X2 introduces the key factor k2 to the auxiliary power amplifier. By changing k1, k2, and the stagnation radian τ at the unit angular frequency of the input signal d , calculate the drain voltage and drain current waveforms of the main power amplifier in four operating states and the drain voltage and drain current waveforms of the auxiliary power amplifier operating at the third harmonic in two operating states respectively, and derive several impedance solutions to form an impedance space of a switching-mode hybrid generalized parallel EF class power amplifier based on active third-harmonic injection at the output terminal.

[0047] The λ / 4 transmission line connected between the drain of the main power amplifier transistor and the drain power supply V dd1 provides a short-circuit state for even harmonics and an open-circuit state for odd harmonics, and at the same time controls the peak value of the drain voltage of the main power amplifier transistor to 2V dd1 .

[0048] The inductance-capacitance third-harmonic resonance circuit shows a short circuit at the third harmonic and an open circuit at other harmonics; the auxiliary power amplifier injects into the main power amplifier through the inductance-capacitance third-harmonic resonance circuit.

[0049] The following further describes this embodiment through the switching current and voltage waveform expressions obtained during the derivation process of the main power amplifier and the auxiliary power amplifier in each stage, as well as the derivation steps, and the parameter expressions of each component of the load networks of the main power amplifier and the auxiliary power amplifier: The switching states of the main power amplifier transistor include the first stage, the second stage, the third stage, and the fourth stage; when the switching state of the transistor is in the first stage, the phase is within 0 to , and the switching state of the transistor is in the closed state; when the switching state of the transistor is in the second stage, the phase is within to , and the switching state of the transistor is in the off state; when the switching state of the transistor is in the third stage, the phase is within to , and the switching state of the transistor is in the off state; when the switching state of the transistor is in the fourth stage: the phase is within to Within this range, the switching state of the transistor is in the off state; is the stagnation radian at the unit angular frequency of the input signal. For the convenience of analysis, the duty cycle D of the gate signal and the stagnation radian at the unit angular frequency of the input signal are introduced , and their relationship is .

[0050] The main power amplifier transistor acts as a switch, and the main power amplifier switch voltage and current meet the four optimal ideal conditions of ZVS, ZVDS, ZCS, and ZCDS:

[0051]

[0052]

[0053]

[0054] The auxiliary power amplifier switch voltage meets the ZVS condition:

[0055] When analyzing the main power amplifier alone, the auxiliary power amplifier can be equivalent to a current source. See the equivalent schematic diagram of the main power amplifier in Figure 2 , and the current L flowing through the load resistor R is a sinusoidal current and can be expressed as:

[0056] where, is the current amplitude, is the initial phase, is the phase.

[0057] The auxiliary power amplifier can be equivalent to a current source, and the third-harmonic injection current can be expressed as:

[0058] where, is the current amplitude, is the initial phase.

[0059] When the switching state of the main power amplifier transistor is in the first stage, the phase is within 0 to . In this working state, the transistor is in the on state and the main switch is closed. In this case, the current flowing through the parallel capacitor C1 (i.e., the first capacitor) and the voltage across its two ends are all zero, as shown in the following equation:

[0060]

[0061] Therefore, the switching current consists of four parts: the inductor current , the λ / 4 transmission line current , the third harmonic injection current and the load current , as shown in the following equation:

[0062] The inductor current can be obtained from the relationship between the inductor current and voltage and the inductor current as follows:

[0063] where Vdd1 is the drain voltage of the main power amplifier; From the fourth operating state where the switch is off and it can be known that the current of the first inductor L1 at a phase of 0 is

[0064] Also, from the ZVDS condition, it can be known that the current of the first capacitor C1 at a phase of 0 is

[0065] Therefore it can finally be expressed as:

[0066] Then the main switch current can be expressed as:

[0067] When the switching state of the main power amplifier transistor is in the second stage, the phase is in the range from to π, the main switch is off, and the main switch current and the λ / 4 transmission line current are both zero, as shown in the following equation:

[0068]

[0069] At this time, the current flowing through the parallel capacitor C1 is as shown in the following equation:

[0070] Taking the derivative of both sides of the above equation gives:

[0071] And , so the voltage across the parallel inductor L1 (i.e., the first inductor) at this time is as shown in the following equation:

[0072] A second-order linear non-homogeneous differential equation can be obtained:

[0073] where p is the first parameter of the main power amplifier, r1 is the second parameter of the main power amplifier, and k1 is the third parameter of the main power amplifier, which are respectively as shown in the following equations:

[0074]

[0075]

[0076] The normalized general solution of this second-order non-homogeneous linear differential equation is:

[0077] From the switch voltage boundary conditions at this time:

[0078]

[0079] The parameters A1 and A2 can be obtained as:

[0080]

[0081] When the switching state of the main power amplifier transistor is in the third stage, the phase is in the range from to . At this time, the main switch is still off, so the main switch current and the main switch voltage are as shown in the following equations:

[0082]

[0083] The current flowing through the parallel capacitor C1 at this time is as shown in the following equation (33): (33) At this time, the inductor voltage and the inductor current are respectively shown as follows:

[0084]

[0085] And it can be known from the second working state that:

[0086] Therefore, it is necessary to make

[0087] Then it can finally be expressed as:

[0088] At this time, the inductor current can finally be expressed as:

[0089] It can be known from Equation (33) that the current of the λ / 4 transmission line in the third stage is shown as follows:

[0090] From the characteristic that the current period of the λ / 4 transmission line is π, the current in the third stage is shown as follows:

[0091] Therefore, the switch current can finally be expressed as:

[0092] It can be simplified to:

[0093] And for the DC component I0 of the switch current the Fourier expansion can be obtained as:

[0094] When the switching state of the main power amplifier transistor is in the fourth stage, the phase is in the range from to At this time, the main switch is still in the off state. At this time, the voltage across the capacitor is similar to the voltage in the second stage and is shown as follows:

[0095] At this time, the switching voltage boundary conditions are:

[0096]

[0097] The parameters A3 and A4 can be obtained as follows:

[0098]

[0099] The DC component of the main power amplifier switching voltage is V dd1 The Fourier expansion is carried out as shown in the following formula:

[0100] Taking the third parameter k1 as a random variable and specifying the stagnation angle , by simultaneously solving , , and , the first parameter p, the second parameter r1, the initial phase of the current flowing through the load resistor and the initial phase of the third harmonic injection current are obtained.

[0101] The fundamental frequency quadrature component V of the main power amplifier switching voltage R and V X1 are as shown in the following formula:

[0102]

[0103] The third harmonic quadrature component V of the main power amplifier switching voltage Rinj and V Xinj are as shown in the following formula:

[0104]

[0105] The load impedance R of the main power amplifier L Using the fundamental frequency quadrature component V of the switching voltage R , from the output power it can be expressed as shown in the following formula:

[0106] The parallel inductor L1 (i.e., the first inductor) of the main power amplifier, using the first parameter p, from it can be expressed as shown in the following formula:

[0107] The parallel capacitor C1 of the main power amplifier utilizes the first parameter p and the third parameter k1 and is determined by and It can be expressed as shown in the following formula:

[0108] The series first reactance X1 can be determined by It is expressed as shown in the following formula:

[0109] Where is the quadrature component V R of the fundamental frequency of the switching voltage of the main power amplifier and V X1 phase shift; The third-harmonic injection current can be determined by the second parameter It is expressed as the following formula:

[0110] For a given output capacitor C out , drain voltage V dd1 , output power P out , the maximum operating frequency of the main power amplifier is expressed as shown in the following formula:

[0111] Where , is an important parameter of the maximum operating frequency of the main power amplifier; Based on the switching-type hybrid generalized parallel class-EF power amplifier with active third-harmonic injection at the output, its normalized power output capacity c p is as shown in the following formula:

[0112] When analyzing the auxiliary power amplifier separately, the load circuit of the auxiliary power amplifier can be equivalently regarded as a load circuit composed of the resistance R Rinj generated by the quadrature components V Xinj and reactance X inj of the switching voltage of the main power amplifier at the third harmonic in series. See the equivalent schematic diagram of the auxiliary power amplifier in inj . The operating frequency of the auxiliary power amplifier is three times the operating frequency of the main power amplifier. The switching state of the auxiliary power amplifier transistor includes a first stage and a second stage; when the switching state of the auxiliary power amplifier transistor is in the first stage, the phase Figure 3 is in the range of 0 to , and the switching state of the transistor is in the closed state; when the switching state of the transistor is in the second stage, the phase is in in to range, the switching state of the transistor is off state.

[0113] When the switching state of the auxiliary power amplifier transistor is in the first stage, the phase is from 0 to range, the switching state of the transistor is on state, so the voltage across the second capacitor C2 and the current are both zero, as shown in the following equations respectively:

[0114]

[0115] Therefore, the auxiliary switch current can be expressed as:

[0116] where is the current flowing through the inductor L2, is the DC current flowing through the RFC.

[0117] At this time, the voltage across the DC-blocking capacitor is as shown in the following equation:

[0118] where V dd2 is the drain supply voltage of the auxiliary power amplifier, is the first parameter of the auxiliary power amplifier; Therefore, the voltage across the second inductor L2 can be expressed as:

[0119] The current flowing through the second inductor L2 can be expressed as:

[0120] From the fact that the current flowing through the second capacitor C2 is zero when the phase is the following equation can be obtained:

[0121] Therefore, the current flowing through the second inductor L2 when the phase is 0 is as shown in the following equation:

[0122] Therefore, the auxiliary switch current can finally be expressed as:

[0123] For the convenience of calculation, the auxiliary switch current is simplified to:

[0124] where r2 is the second parameter of the auxiliary power amplifier, as shown in the following formula:

[0125] When the switching state of the auxiliary power amplifier transistor is in the second stage, the phase is in to range, the switching state of the transistor is off, and the auxiliary switch current is zero, as shown in the following formula:

[0126] The inductor voltage is as shown in the following formula:

[0127] Therefore, the current through the second capacitor C2 can be expressed as

[0128] Taking the derivative of both sides of the above formula and substituting with , a second-order linear non-homogeneous differential equation can be obtained:

[0129] where k2 (i.e., the second key factor) is the third parameter of the auxiliary power amplifier as shown in the following formula:

[0130] Its normalized general solution is:

[0131] From the boundary conditions:

[0132]

[0133] The expressions of A5 and A6 can be obtained as:

[0134]

[0135] The third harmonic orthogonal components V S2a and V S2b of the auxiliary power amplifier switching voltage are respectively as shown in the following formulas:

[0136]

[0137] Where V S2a and V S2b According to Kirchhoff's law, respectively Rinj and V Xinj The relationship is shown as follows:

[0138]

[0139] Auxiliary amplifier drain power supply voltage V dd2 The Fourier expansion is shown as follows:

[0140] The third parameter k2 (i.e., the second key factor) of the auxiliary amplifier is taken as a random variable, and the and , get the first parameter of the auxiliary amplifier and the second parameter r1.

[0141] The parallel inductance L2 (i.e., the second inductance) of the auxiliary power amplifier is expressed as follows using the first parameter p of the main power amplifier, the second parameter r1 of the main power amplifier, and the second parameter r2 of the auxiliary power amplifier:

[0142] The parallel capacitor C2 (i.e., the second capacitor) of the auxiliary power amplifier uses the first parameter p of the main power amplifier, the second parameter r1 of the main power amplifier, the second parameter r2 of the auxiliary power amplifier, and the third parameter k2 (i.e., the second key factor) of the auxiliary power amplifier as shown in the following formula:

[0143] The second reactance X2 of the auxiliary power amplifier is expressed as follows using the first parameter p of the main power amplifier and the second parameter r1 of the main power amplifier:

[0144] The load circuit of the auxiliary power amplifier is the third harmonic equivalent resistance R of the main power amplifier. inj and reactance X inj The first parameter p of the main power amplifier and the second parameter r1 of the main power amplifier are shown as follows:

[0145]

[0146] The present embodiment is further described below through experimental results: Referring to Figure 4, the normalized drain voltage waveform and current waveform of the generalized parallel class-EF power amplifier based on active third-harmonic injection at the output end in this embodiment are shown under specified , , in ideal calculation and simulation verification respectively. Among them, Figure 4a is the normalized drain voltage waveform and current waveform of the main power amplifier in this embodiment in ideal calculation and simulation verification respectively; Figure 4b is the normalized drain voltage waveform and current waveform of the auxiliary power amplifier in this embodiment in ideal calculation and simulation verification respectively.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than limit the scope of its protection. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that after reading the present invention, various changes, modifications or equivalent replacements can still be made to the specific implementation manners of the invention. However, these changes, modifications or equivalent replacements are all within the scope of the claims of the invention pending approval.

Claims

1. A generalized parallel class EF power amplifier based on active third harmonic injection at the output, characterized in that: It includes a main power amplifier and an auxiliary power amplifier. The main power amplifier includes a main switch, a first capacitor, a first inductor, a first ideal DC-isolating capacitor, λ / 4 transmission line, main amplifier drain power supply, inductor capacitor third harmonic resonant circuit and inductor capacitor resonant circuit, λ is the wavelength; The main power amplifier is connected to the auxiliary power amplifier through an inductor-capacitor third harmonic resonant circuit, and a second reactance is arranged between the inductor-capacitor third harmonic resonant circuit and the auxiliary power amplifier; The main switch is the main power amplifier transistor, the drain of the main power amplifier transistor is connected through λ / 4 transmission line is connected to the main amplifier drain power supply; One end of the main switch is connected to one end of the first capacitor, one end of the first inductor, λ One end of a / 4 transmission line, one end of an inductor-capacitor third harmonic resonant circuit, and one end of an inductor-capacitor resonant circuit; The other end of the first inductor is connected to one end of the first ideal DC blocking capacitor. λ The other end of the / 4 transmission line is connected to the main power amplifier drain power supply, and the other end of the inductor-capacitor resonant circuit is connected to one end of the output load; a first reactance is set between the other end of the inductor-capacitor resonant circuit and one end of the output load; The other end of the main switch is respectively connected to the other end of the first capacitor, the other end of the first ideal DC blocking capacitor and the other end of the output load; The first reactance and the second reactance are variable reactances.

2. The generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 1, characterized in that: The auxiliary power amplifier includes an auxiliary switch, a second capacitor, a second inductor, a second ideal DC blocking capacitor and an RFC; One end of the auxiliary switch is respectively connected to one end of the second capacitor, one end of the second inductor, one end of the RFC and one end of the second reactance; The other end of the second inductor is connected to one end of the second ideal DC blocking capacitor, and the other end of RFC is connected to the auxiliary power amplifier drain power supply; The other end of the auxiliary switch is respectively connected to the other end of the second capacitor and the other end of the second ideal DC blocking capacitor; The auxiliary switch is an auxiliary power amplifier transistor, and the drain of the auxiliary power amplifier transistor is connected to the auxiliary power amplifier drain power supply through the RFC.

3. The generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 1, characterized in that: The inductor-capacitor third harmonic resonant circuit comprises a third capacitor and a third inductor, one end of the third capacitor is connected to one end of the main switch, the other end of the third capacitor is connected to one end of the third inductor, the other end of the third inductor is connected to one end of the second reactance; the other end of the second reactance is connected to one end of the auxiliary switch; The inductor-capacitor resonant circuit includes a fourth capacitor and a fourth inductor, one end of the fourth inductor is connected to one end of the main switch, the other end of the fourth inductor is connected to one end of the fourth capacitor, the other end of the fourth capacitor is connected to one end of the first reactance, and the other end of the first reactance is connected to one end of the output load.

4. A design method for a generalized parallel EF class power amplifier based on active third harmonic injection at the output end, using the generalized parallel EF class power amplifier based on active third harmonic injection at the output end as claimed in any one of claims 1 to 3, characterized in that: The steps include: The main power amplifier and the auxiliary power amplifier are both in the switch mode. The main power amplifier forms a parallel EF mode through the λ / 4 transmission line and the first inductor. The auxiliary power amplifier works at the triple frequency. The harmonics generated by the auxiliary power amplifier are injected into the output end of the main power amplifier through the third harmonic resonant circuit of the inductor and capacitor. The first key factor is introduced by connecting the first reactance in series in the main power amplifier, and the second key factor is introduced by connecting the second reactance in series in the auxiliary power amplifier. By changing the first key factor, the second key factor and the stagnation radian of the input signal at unit angular frequency, the drain voltage and drain current waveforms of the main power amplifier and the auxiliary power amplifier in various working states are calculated, and several impedance solutions are derived to form the impedance space of a switch-type hybrid generalized parallel EF class power amplifier based on active third harmonic injection at the output end.

5. The design method of a generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 4, characterized in that: λ / 4The period of the transmission line current is , the switching states of the main power amplifier transistor include the first stage, the second stage, the third stage and the fourth stage; The switching state of the main power amplifier transistor is in the closed state in the first stage, and the phase is between 0 and within the scope; When the switching state of the main power amplifier transistor is in the first stage, the current expression of the main switch is: in, is the main switch current in the first stage, For the simplified first stage main switch current, is the initial phase of the current flowing through the load resistance, is the phase, is the initial phase of the third harmonic injection current, V dd1 is the main power amplifier drain supply voltage, p The first parameter of the main amplifier is r 1 is the second parameter of the main amplifier; The switching state of the main power amplifier transistor is in the disconnected state in the second stage, and the phase is arrive within the scope; When the switching state of the main power amplifier transistor is in the second stage, the voltage second-order linear non-homogeneous differential equation of the main switch is expressed as: in, p The first parameter of the main amplifier is r 1 is the second parameter of the main amplifier, k 1 is the first key factor, is the voltage across the capacitor in the second stage; When the switching state of the main power amplifier transistor is in the second stage, the normalized general solution of the second-order linear non-homogeneous differential equation of the voltage of the main switch is: The switching state of the main power amplifier transistor is in the disconnected state when it is in the third stage. arrive within the scope; When the switching state of the main power amplifier transistor is in the third stage, the voltage expression of the main switch is: in, is the voltage across the capacitor in the third stage; The switching state of the main power amplifier transistor is in the fourth stage, which is the disconnected state. arrive Within the range; when the switching state of the main power amplifier transistor is in the fourth stage, the voltage expression of the main power amplifier is: in, is the voltage across the capacitor in the fourth stage; Said is the stagnation radian at the unit angular frequency of the input signal. The relationship between the stagnation radian at the unit angular frequency of the input signal and the duty cycle of the gate signal is expressed as follows: in, D is the duty cycle of the gate signal, is the stagnation radian at unit angular frequency of the input signal; The load impedance is represented by the orthogonal components of the fundamental frequency of the switching voltage and the output power, the first inductance is represented by the first parameter, the first capacitance is represented by the first parameter and the first key factor, the first reactance is represented by the orthogonal components of the fundamental frequency of the switching voltage of the main power amplifier, and the third harmonic injection current of the main power amplifier is represented by the second parameter.

6. The design method of a generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 5, characterized in that: The expression for load impedance is: Where R is the load impedance, V R is the orthogonal resistance component of the switching voltage fundamental frequency, P out is the output power; The expression of the first inductance is: in, L 1 is the first inductor, p The first parameter of the main amplifier is V dd1 is the main power amplifier drain supply voltage, The expression of the first capacitance is: in, C 1 is the first capacitor, k 1 is the first key factor; The expression of the first reactance is: in, X 1 is the first reactance, V X1 It is the fundamental frequency orthogonal reactance component of the main power amplifier switching voltage; The expression of the third harmonic injection current of the main power amplifier is: in, Injects the third harmonic current into the main amplifier. p The first parameter of the main amplifier is r 1 is the second parameter of the main amplifier.

7. The design method of a generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 5, characterized in that: The third harmonic resonant circuit of the inductor and capacitor behaves as a short circuit at the third harmonic and as an open circuit at other harmonics; The λ / 4 transmission line is short-circuited at even harmonics and open-circuited at odd harmonics; The peak value of the drain voltage of the main power amplifier transistor is controlled to be twice the drain supply voltage.

8. The design method of a generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 4, characterized in that: The operating frequency of the auxiliary power amplifier is three times the operating frequency of the main power amplifier, and the switching state of the auxiliary power amplifier transistor includes a first stage and a second stage; The switch state of the auxiliary power amplifier transistor is closed in the first stage, and the phase From 0 to within the scope; When the switching state of the auxiliary power amplifier transistor is in the first stage, the current expression of the auxiliary switch is: in, is the auxiliary switch first stage current, is the simplified auxiliary switch first stage current, is the phase, L 2 is the second inductor, V dd1 is the main power amplifier drain supply voltage, The first parameter of the auxiliary amplifier is r 2 is the second parameter of the auxiliary amplifier. The initial phase of the third harmonic injection current; The switching state of the auxiliary power amplifier transistor is in the disconnected state in the second stage, and the phase exist arrive within the scope; When the switching state of the auxiliary power amplifier transistor is in the second stage, the second-order linear non-homogeneous differential equation of the voltage of the auxiliary switch is: in, k 2 is the second key factor, is the voltage across the second capacitor; When the switching state of the auxiliary power amplifier transistor is in the second stage, the normalized general solution of the second-order linear non-homogeneous differential equation of the voltage of the auxiliary switch is: ； The second inductance is expressed by the first parameter of the main power amplifier, the second parameter of the main power amplifier, and the second parameter of the auxiliary power amplifier; the second capacitance is expressed by the first parameter of the main power amplifier, the second parameter of the main power amplifier, the second parameter of the auxiliary power amplifier, and the third parameter of the auxiliary power amplifier; the second reactance is expressed by the first parameter of the main power amplifier and the second parameter of the main power amplifier; the load circuit of the auxiliary power amplifier is equivalent to the third harmonic equivalent resistance of the main power amplifier and the third harmonic equivalent reactance of the main power amplifier, and the third harmonic equivalent resistance of the main power amplifier and the third harmonic equivalent reactance of the main power amplifier are expressed by the first parameter of the main power amplifier and the second parameter of the main power amplifier.

9. The design method of a generalized parallel EF class power amplifier based on active third harmonic injection at the output end according to claim 8, characterized in that: The expression of the second inductance is: in, L 2 is the second inductor, p The first parameter of the main amplifier is r 2 is the second parameter of the auxiliary amplifier. V R is the orthogonal resistance component of the switching voltage fundamental frequency, V dd1 is the main power amplifier drain supply voltage, r 1 is the second parameter of the main amplifier, P out is the output power; The expression of the second capacitance is: ； in, C 2 is the second capacitor, k 2 is the second key factor; The expression of the second reactance is: in, X 2 is the second reactance, V S2b is the second orthogonal component of the third harmonic of the auxiliary power amplifier switching voltage, Injects the third harmonic current into the main amplifier. V Xinj The orthogonal reactance component of the main power amplifier switching voltage at the third harmonic; The expression of the third harmonic equivalent resistance of the main power amplifier is: in, R inj is the third harmonic equivalent resistance of the main power amplifier, V Rinj is the orthogonal resistance component of the main power amplifier switching voltage at the third harmonic; The expression of the third harmonic equivalent reactance of the main power amplifier is: in, X inj It is the third harmonic equivalent reactance of the main power amplifier.

10. A transmitter, characterized in that: The invention comprises a generalized parallel EF class power amplifier based on active third harmonic injection at the output end as described in any one of claims 1 to 3.

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