A millimeter-wave power amplifier for automotive radar transceivers

Abstract

The present invention discloses a millimeter wave power amplifier for an automobile radar transceiver, comprising an input predistortion linearization differential amplifier network, a first final-stage high-power amplifier network, a second final-stage high-power amplifier network, and an output differential-to-single-ended matching network. The core architecture of the present invention adopts a two-way synthesized final-stage high-power amplifier network to have high power, high efficiency, and high gain characteristics in the millimeter wave frequency band. At the same time, the high-frequency parasitic parameter suppression characteristics of the differential amplifier structure and the analog predistortion linearization technology combined with the input predistortion linearization differential amplifier network are utilized, so that the entire power amplifier obtains good high gain, high efficiency, high linearity, and high power output capability in the frequency band of automobile radar application.

Description

Technical Field

[0001] The present invention relates to the field of field effect transistor radio frequency power amplifiers and integrated circuits, and in particular to a high-power, high-efficiency, high-linearity power amplifier applied to a transceiver transmitting module of an automobile radar system. Background Art

[0002] With the rapid development of automotive radar systems and RF microwave circuits, automotive radar RF front-end transceivers are also developing towards high performance, high integration, and low power consumption. Therefore, the market urgently needs the power amplifier of the automotive radar transmitter to have high output power, high linearity, high gain, high efficiency, and low cost. However, when the integrated circuit process is used to design the power amplifier chip circuit of the automotive radar system, its performance is subject to certain restrictions, mainly reflected in:

[0003] (1) Limited high power and high efficiency capabilities: Traditional power amplifiers use a multi-path parallel synthesis structure or a distributed structure. The synthesis efficiency of these two structures is limited, resulting in a portion of power loss in the synthesis network, which limits the high power and high efficiency capabilities.

[0004] (2) Limited linearity index and high efficiency capability: Traditional power amplifiers are affected by the parasitic nonlinear capacitance of transistors, especially when operating near saturation. The linearity index is low, so power back-off is often required, sacrificing high power output capability and high efficiency index to improve linearity index.

[0005] The typical method of high-power, high-efficiency, high-linearity amplifiers is to use a digital pre-distortion combined with a Doherty power amplifier structure, but this method also has certain limitations. The traditional digital pre-distortion combined with the Doherty power amplifier structure is often limited by transistor parasitic parameters and the bandwidth of the digital pre-distortion system when used in the frequency band of automotive radar systems. The improvement in linearity and efficiency is relatively limited, and its circuit structure is relatively complex, which is not conducive to low-cost indicators. At the same time, when implementing an amplifier in the frequency band of automotive radar systems based on a traditional single transistor structure or Cascode transistor, the gain is often low. If the traditional analog pre-distortion method is used, a certain gain needs to be sacrificed to improve linearity, which further deteriorates the gain index of such solutions.

[0006] From this, it can be seen that the design difficulties of high-power, high-efficiency, and high-linearity amplifiers for automotive radar system applications based on integrated circuit technology are: high-power and high-efficiency output are difficult; linearity indicators and high-efficiency capabilities are limited and there are many limitations. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a millimeter-wave power amplifier for an automotive radar transceiver, which combines the advantages of transistor stacking technology, differential amplifier technology, and analog pre-distortion linearization technology, and has the advantages of high power, high efficiency, high linearity and low cost in the automotive radar application frequency band.

[0008] The technical solution of the present invention to solve the above technical problems is as follows: A millimeter wave power amplifier for an automotive radar transceiver comprises an input predistortion linearization differential amplifier network, a first final stage high power amplifier network, a second final stage high power amplifier network and an output differential to single-ended matching network;

[0009] The input end of the input predistortion linear differential amplifier network is the input end of the entire power amplifier, and the first output end and the second output end thereof are respectively connected to the input ends of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network, and the phase difference between the first output end and the second output end signal of the input predistortion linear differential amplifier network is 180 degrees;

[0010] The output ends of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network are respectively connected to the first input end and the second input end of the output differential-to-single-ended matching network. The output end of the output differential-to-single-ended matching network is the output end of the entire power amplifier. The phases of the signals at the first input end and the second input end of the output differential-to-single-ended matching network differ by 180 degrees.

[0011] The beneficial effects of the present invention are as follows: the input pre-distortion linear differential amplifier network used in the present invention can not only realize the driving amplifier and power distribution of the input RF signal, but also perform impedance matching and phase adjustment on the RF input signal, and realize the conversion of the single-ended signal to the differential signal, thereby ensuring the phase difference of the differential signal. The most critical thing is that the analog pre-distortion linearization technology is adopted. When the power amplifier works with a large signal, the input pre-distortion linear differential amplifier network realizes the power expansion characteristic, thereby offsetting the power compression characteristics of the first final high-power amplifier network and the second final high-power amplifier network, thereby significantly improving the linearity index of the entire amplifier.

[0012] Furthermore, the input end of the input predistortion linear differential amplifier network is connected to capacitor C1, the other end of capacitor C1 is connected to inductor L1, the other end of inductor L1 is connected to grounded capacitor C2, inductor L3 and inductor L2, and the other end of inductor L2 is connected to grounded capacitor C3 and gate power supply port V g1 , the other end of the inductor L3 is connected to the field effect transistor M d The gate of the field effect transistor M d The source of the field effect tube M is grounded. dThe drain of the inductor L4 is connected to the capacitor C4 and the inductor L5. The other end of the inductor L5 is connected to the non-same-name end of the primary coil of the coupling transformer T1. The same-name end of the primary coil of the coupling transformer T1 is connected to the inductor L6. The other end of the inductor L6 is connected to the grounded capacitor C5 and the drain power supply port V d1 The same-name end and non-same-name end of the secondary coil of transformer T1 are connected to the first and second output ends of the input pre-distortion linear differential amplifier network, and the middle tap end of the secondary coil of T1 is connected to the gate power supply port V g2 And ground capacitor C8, one end of capacitor C4 is connected to field effect tube M e The drain of the resistor R1, the other end of the resistor R1 is connected to the field effect tube M e The source and resistor R2, the other end of resistor R2 is connected to the source power supply port V s1 ; Field effect tube M e The source of the capacitor C6 is connected to the ground, and the field effect tube M e The gate of the capacitor C7 and the resistor R3 are connected to the ground, and the other end of the resistor R3 is connected to the power supply port V s2 .

[0013] The beneficial effect of the above further solution is: through the V s1 and port V s2 For transistor M e The regulation effect can realize the strength control of the circuit pre-distortion signal, so as to have the adjustability when optimizing linearity. At the same time, the driving amplifier structure provides good linear gain, which makes up for the loss of amplifier gain caused by the pre-distortion circuit structure.

[0014] Furthermore, the input ends of the first final high-power amplifier network and the second final high-power amplifier network are both connected to the inductor L gj The b-end, inductor L gj The a terminal is connected to the ground capacitor C pj 、Inductance L pj and inductor L qj , inductance L qj The other end is connected to the field effect tube M qj The gate, M qj The source of M is grounded. qj The drain is connected to the microstrip line TL qj , microstrip line TL qj The other end is connected to the field effect tube M tj The source, M tj The gate-to-ground capacitance C tj and resistor R tj , resistor R tj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b terminal, resistor R qjThe b terminal of the field effect tube M is grounded. tj The drain is connected to the microstrip line TL tj , microstrip line TL tj The other end is connected to the field effect tube M nj The source of the field effect tube M nj The gate-to-ground capacitance C nj and resistor R nj , resistor R nj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b-end of the field effect tube M nj The drain is connected to the microstrip line TL nj , microstrip line TL nj The other end is connected to the resistor R uj The a terminal and the inductor L u1 The b end of the inductor L pj The other end is connected to the field effect tube M pj The gate, M pj The source of M is grounded. pj The drain is connected to the microstrip line TL pj , microstrip line TL pj The other end is connected to the field effect tube M sj The source of the field effect tube M sj The gate resistor R sj and grounding capacitor C sj , resistor R sj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b-end of the field effect tube M sj The drain is connected to the microstrip line TL sj , TL sj The other end is connected to the effect tube M mj The source, M mj The gate-to-ground capacitance C mj and resistor R mj , resistor R mj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b end, M mj The drain is connected to the microstrip line TL mj , microstrip line TL mj The other end is connected to the resistor R uj The a terminal and the inductor L uj The b end of the inductor L u1 The a terminal is connected to the ground capacitor C uj and inductor L vj , inductance L vj The other end is the output end of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network, where j=1 and 2.

[0015] The beneficial effect of the above further scheme is that the core circuit used in the first final-stage high-power amplifier network and the second final-stage high-power amplifier network of the present invention is a differential amplifier circuit based on a pair of self-biased three-transistor stacked dual-path synthesis structure. This structure can significantly improve the power capacity and power gain of the power amplifier, while improving the sensitivity of the traditional stacked structure to parasitic parameters in the millimeter wave frequency band.

[0016] Furthermore, the first and second input terminals of the output differential to single matching network are connected to the same-name terminal and the non-same-name terminal of the secondary coil of the transformer T2, and the inductor L7 is connected to the middle tap terminal of the transformer T2, and the other end of the inductor L7 is connected to the grounded capacitor C9 and the drain power supply port V d2 The same-name end of the primary coil of transformer T2 is connected to capacitor C 10 , capacitor C 10 The other end is the output end of the output differential to single matching network, and the non-same-name end of the primary coil of the transformer T2 is grounded.

[0017] The beneficial effect of the above further scheme is that the output differential-to-single-ended matching network adopted by the present invention can not only realize the power synthesis of differential RF signals, but also convert differential signals into single-ended signals, introducing less insertion loss, while ensuring the output power and efficiency of the amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a principle block diagram of the power amplifier of the present invention;

[0019] Figure 2 This is a circuit diagram of a power amplifier according to the present invention. DETAILED DESCRIPTION

[0020] Now, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the accompanying drawings are only exemplary and are intended to explain the principles and spirit of the present invention, rather than to limit the scope of the present invention.

[0021] An embodiment of the present invention provides a millimeter wave power amplifier for an automobile radar transceiver, comprising an input predistortion linearization differential amplifier network, a first final stage high power amplifier network, a second final stage high power amplifier network, and an output differential to single-ended matching network.

[0022] like Figure 1 The input end of the input predistortion linear differential amplifier network is the input end of the entire power amplifier, and the first output end and the second output end are respectively connected to the input ends of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network, and the phase difference between the first output end and the second output end of the input predistortion linear differential amplifier network is 180 degrees;

[0023] The output ends of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network are respectively connected to the first input end and the second input end of the output differential-to-single-ended matching network. The output end of the output differential-to-single-ended matching network is the output end of the entire power amplifier. The phases of the first and second input end signals of the output differential-to-single-ended matching network differ by 180 degrees.

[0024] like Figure 2 As shown, the input end of the input predistortion linear differential amplifier network is connected to capacitor C1, the other end of capacitor C1 is connected to inductor L1, the other end of inductor L1 is connected to grounded capacitor C2, inductor L3 and inductor L2, and the other end of inductor L2 is connected to grounded capacitor C3 and gate power supply port V g1 , the other end of the inductor L3 is connected to the field effect transistor M d The gate of the field effect transistor M d The source of the field effect tube M is grounded. d The drain of the inductor L4 is connected to the capacitor C4 and the inductor L5. The other end of the inductor L5 is connected to the non-same-name end of the primary coil of the coupling transformer T1. The same-name end of the primary coil of the coupling transformer T1 is connected to the inductor L6. The other end of the inductor L6 is connected to the grounded capacitor C5 and the drain power supply port V d1 The same-name end and non-same-name end of the secondary coil of transformer T1 are connected to the first and second output ends of the input pre-distortion linear differential amplifier network, and the middle tap end of the secondary coil of T1 is connected to the gate power supply port V g2 And ground capacitor C8, one end of capacitor C4 is connected to field effect tube M e The drain of the resistor R1, the other end of the resistor R1 is connected to the field effect tube M e The source and resistor R2, the other end of resistor R2 is connected to the source power supply port V s1 ; Field effect tube M e The source of the capacitor C6 is connected to the ground, and the field effect tube M e The gate of the capacitor C7 and the resistor R3 are connected to the ground, and the other end of the resistor R3 is connected to the power supply port V s2 .

[0025] The input terminals of the first high-power amplifier network and the second high-power amplifier network are connected to the inductor L gj The b-end, inductor L gj The a terminal is connected to the ground capacitor C pj 、Inductance L pj and inductor L qj , inductance L qj The other end is connected to the field effect tube M qj The gate, M qj The source of M is grounded. qj The drain is connected to the microstrip line TL qj , microstrip line TL qj The other end is connected to the field effect tube Mtj The source, M tj The gate-to-ground capacitance C tj and resistor R tj , resistor R tj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b terminal, resistor R qj The b terminal of the field effect tube M is grounded. tj The drain is connected to the microstrip line TL tj , microstrip line TL tj The other end is connected to the field effect tube M nj The source of the field effect tube M nj The gate-to-ground capacitance C nj and resistor R nj , resistor R nj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b-end of the field effect tube M nj The drain is connected to the microstrip line TL nj , microstrip line TL nj The other end is connected to the resistor R uj The a terminal and the inductor L u1 The b end of the inductor L pj The other end is connected to the field effect tube M pj The gate, M pj The source of M is grounded. pj The drain is connected to the microstrip line TL pj , microstrip line TL pj The other end is connected to the field effect tube M sj The source of the field effect tube M sj The gate resistor R sj and grounding capacitor C sj , resistor R sj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b-end of the field effect tube M sj The drain is connected to the microstrip line TL sj , TL sj The other end is connected to the effect tube M mj The source, M mj The gate-to-ground capacitance C mj and resistor R mj , resistor R mj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b end, M mj The drain is connected to the microstrip line TL mj , microstrip line TL mj The other end is connected to the resistor R ujThe a terminal and the inductor L uj The b end of the inductor L u1 The a terminal is connected to the ground capacitor C uj and inductor L vj , inductance L vj The other end is the output end of the first final stage high power amplifier network and the second final stage high power amplifier network. Wherein, j=1,2.

[0026] The first and second input terminals of the output differential to single matching network are connected to the same-name terminal and non-same-name terminal of the secondary coil of transformer T2, and the inductor L7 is connected to the middle tap terminal of transformer T2. The other end of the inductor L7 is connected to the grounded capacitor C9 and the drain power supply port V d2 The same-name end of the primary coil of transformer T2 is connected to capacitor C 10 , capacitor C 10 The other end is the output end of the output differential to single matching network, and the non-same-name end of the primary coil of the transformer T2 is grounded.

[0027] Combine the following Figure 2 The specific working principle and process of the present invention are introduced:

[0028] The RF input signal is passed through the input terminal RF in Entering the pre-distortion linearization differential amplifier network, first the input impedance transformation matching and drive signal amplification are performed, and then the pre-distortion control network is entered. When the input signal is in the small signal state, the M in the pre-distortion network e The transistor is not turned on; when the input signal is in the large signal state, the M in the predistortion network e The transistor is turned on to improve the large signal power compression characteristics, and then it is converted into a differential signal after passing through T1 and enters the input end of the first final high-power amplifier network and the second final high-power amplifier network at the same time. After power amplification through the amplifier network, it is output from the output end of the first final high-power amplifier network and the second final high-power amplifier network in the form of a differential signal. After passing through the output differential to single-ended matching network, the two signals are combined into a single-ended signal from the output end RF out Output.

[0029] Based on the above circuit analysis, the millimeter wave power amplifier for automotive radar transceiver proposed by the present invention is different from the previous amplifier structure based on integrated circuit technology in that the core architecture adopts a differential two-way current synthesis self-biased three-stack amplifier and combines an analog pre-distortion linearization driver amplifier:

[0030] The differential two-way current synthesis self-biased three-stack amplifier is very different in structure from the traditional single transistor, so it will not be described here;

[0031] The differential two-way current synthesis self-biased three-stack amplifier adopts an analog pre-distortion linearization drive structure, which improves the problem of the traditional three-stack amplifier that the working linearity deteriorates as the number of transistor stacking times increases. At the same time, the use of a differential stack amplifier suppresses the deterioration of high-frequency parasitic parameters on the millimeter-wave stack amplifier, thereby improving the power capability and efficiency indicators for automotive radar frequency band applications.

[0032] In the entire high-power, high-efficiency, high-linearity power amplifier for automotive radar, the size of the transistor and the size of other resistors and capacitors are determined after comprehensive consideration of various indicators such as the gain, linearity and output power of the entire circuit. Through the subsequent layout design and reasonable layout, the required indicators can be better achieved, and high power output capability, high power gain, and good input-output matching characteristics can be achieved.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A millimeter wave power amplifier for an automotive radar transceiver, characterized in that: It includes an input pre-distortion linearization differential amplifier network, a first final stage high power amplifier network, a second final stage high power amplifier network and an output differential to single-ended matching network; The input end of the input predistortion linear differential amplifier network is the input end of the entire power amplifier, and the first output end and the second output end thereof are respectively connected to the input end of the first final-stage high-power amplifier network and the input end of the second final-stage high-power amplifier network, and the phase difference between the first output end and the second output end of the input predistortion linear differential amplifier network is 180 degrees; The output ends of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network are respectively connected to the first input end and the second input end of the output differential-to-single-ended matching network, the output end of the output differential-to-single-ended matching network is the output end of the entire power amplifier, and the first input end and the second input end of the output differential-to-single-ended matching network have a signal phase difference of 180 degrees; The input end of the input predistortion linear differential amplifier network is connected to capacitor C1, the other end of capacitor C1 is connected to inductor L1, the other end of inductor L1 is connected to grounded capacitor C2, inductor L3 and inductor L2, and the other end of inductor L2 is connected to grounded capacitor C3 and gate power supply port V g1 , the other end of the inductor L3 is connected to the field effect transistor M d The gate of the field effect transistor M d The source of the field effect tube M is grounded. d The drain of the inductor L4 is connected to the capacitor C4 and the inductor L5. The other end of the inductor L5 is connected to the non-same-name end of the primary coil of the coupling transformer T1. The same-name end of the primary coil of the coupling transformer T1 is connected to the inductor L6. The other end of the inductor L6 is connected to the grounded capacitor C5 and the drain power supply port V d1 The same-name end and the non-same-name end of the secondary coil of the transformer T1 are respectively connected to the first and second output ends of the input pre-distortion linear differential amplifier network, and the middle tap end of the secondary coil of the coupling transformer T1 is connected to the gate power supply port V g2 And ground capacitor C8, one end of capacitor C4 is connected to field effect tube M e The drain of the resistor R1, the other end of the resistor R1 is connected to the field effect tube M e The source and resistor R2, the other end of resistor R2 is connected to the source power supply port V s1 ; Field effect tube M e The source of the capacitor C6 is connected to the ground, and the field effect tube M e The gate of the capacitor C7 and the resistor R3 are connected to the ground, and the other end of the resistor R3 is connected to the power supply port V s2 .

2. A millimeter wave power amplifier for an automotive radar transceiver according to claim 1, characterized in that: The input ends of the first final high-power amplifier network and the second final high-power amplifier network are both connected to the inductor L gj The b-end, inductor L gj The a terminal is connected to the ground capacitor C pj 、Inductance L pj and inductor L qj , inductance L qj The other end is connected to the field effect tube M qj The gate, M qj The source of M is grounded. qj The drain is connected to the microstrip line TL qj , microstrip line TL qj The other end is connected to the field effect tube M tj The source, M tj The gate-to-ground capacitance C tj and resistor R tj , resistor R tj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b terminal, resistor R qj The b terminal of the field effect tube M is grounded. tj The drain is connected to the microstrip line TL tj , microstrip line TL tj The other end is connected to the field effect tube M nj The source of the field effect tube M nj The gate-to-ground capacitance C nj and resistor R nj , resistor R nj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b-end of the field effect tube M nj The drain is connected to the microstrip line TL nj , microstrip line TL nj The other end is connected to the resistor R uj The a terminal and the inductor L u1 The b end of the inductor L pj The other end is connected to the field effect tube M pj The gate, M pj The source of M is grounded. pj The drain is connected to the microstrip line TL pj , microstrip line TL pj The other end is connected to the field effect tube M sj The source of the field effect tube M sj The gate resistor R sj and grounding capacitor C sj , resistor R sj The other end is connected to the resistor R qj The a terminal and the resistor R rj The b-end of the field effect tube M sj The drain is connected to the microstrip line TL sj , TL sj The other end is connected to the effect tube M mj The source, M mj The gate-to-ground capacitance C mj and resistor R mj , resistor R mj The other end is connected to the resistor R rj The a terminal and the resistor R uj The b end, M mj The drain is connected to the microstrip line TL mj , microstrip line TL mj The other end is connected to the resistor R uj The a terminal and the inductor L uj The b end of the inductor L u1 The a terminal is connected to the ground capacitor C uj and inductor L vj , inductance L vj The other end is the output end of the first final-stage high-power amplifier network and the second final-stage high-power amplifier network; wherein j=1 and 2.

3. A millimeter wave power amplifier for an automotive radar transceiver according to claim 1, characterized in that: The first input terminal and the second input terminal of the output differential to single matching network are respectively connected to the same-name terminal and the non-same-name terminal of the secondary coil of the transformer T2, and the inductor L7 is connected to the middle tap terminal of the transformer T2, and the other end of the inductor L7 is connected to the grounded capacitor C9 and the drain power supply port V d2 ; The same-name end of the primary coil of transformer T2 is connected to capacitor C 10 , capacitor C 10 The other end is the output end of the output differential to single matching network, and the non-same-name end of the primary coil of the transformer T2 is grounded.

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