A high linearity broadband quadrature modulator

Abstract

The present invention discloses a high-linearity broadband orthogonal modulator, which belongs to the field of integrated circuit signal processing, and includes a phase shifter module, a mixer module and a differential-to-single-ended module. The phase shifter module performs phase shifting on the local oscillator differential input signal to generate a local oscillator orthogonal signal output; the mixer module performs mixing and outputting on the output signal of the phase shifter module and the baseband input signal; the differential-to-single-ended module converts the output differential signal of the mixer module into a single-ended signal and then outputs it. Compared with the traditional orthogonal modulator technology, the local oscillator orthogonal generation of the present invention adopts a multi-phase filter method, which is implemented by resistors and capacitors, has a smaller chip area, and can realize ultra-wideband operation, covering the local oscillator input frequency range of 50MHz to 6GHz; the sideband suppression is about ‑50dBc, and the carrier leakage is about ‑40dBm, which can achieve excellent modulation performance within the broadband operating frequency range. The mixer module adopts inductor peaking, and the differential-to-single-ended module adopts a broadband active balun structure to achieve gain compensation and high linearity.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit signal processing, and in particular to a high-linearity broadband orthogonal modulator. Background Art

[0002] With the rapid development of RF integrated circuit technology, RF circuits are being used more and more widely, especially in the field of wireless communications. The realization of wireless communication systems mainly relies on RF communication circuits. After years of continuous research and accumulation, RF communication circuits have basically formed a typical structure, mainly including modulation, frequency conversion, amplification and demodulation. In recent years, the application fields of RF communication circuits mainly include aerospace communications, radar satellite communications, shipboard communications, personal mobile communications, wireless local area networks, the Internet of Things and the Internet of Vehicles.

[0003] RF circuit parameters directly determine system performance and have become the core part of communication systems. The application requirements of communication technology are becoming higher and higher. This urgently requires wireless communication equipment to provide safe and reliable communication functions at any time and anywhere, and become lighter, smaller and lower in power consumption. For these reasons, the design of RF communication circuits faces more requirements and challenges. In RF communication circuits, mixers are the most core modules in signal transceivers. The mixer can change the frequency of the output signal of the oscillator source, thereby realizing signal modulation and demodulation. The modulator is mainly used in the transmitter to modulate the baseband signal to the RF signal and then output it. Summary of the invention

[0004] The object of the present invention is to provide a high linearity broadband orthogonal modulator to realize a high linearity broadband orthogonal modulator suitable for a radio frequency operating frequency range of 50MHz to 6GHz.

[0005] In order to solve the above technical problems, the present invention provides a high linearity broadband orthogonal modulator, comprising:

[0006] The phase shifter module performs phase shifting on the local oscillator differential input signal to generate a local oscillator quadrature signal output;

[0007] A mixer module, mixing and outputting the output signal of the phase shifter module and the baseband input signal;

[0008] The differential-to-single-ended module converts the output differential signal of the mixer module into a single-ended signal and then outputs it.

[0009] In one embodiment of the present invention, the phase shifter module includes a multi-phase filter and a limiting amplifier connected in sequence; the multi-phase filter shifts the phase of the local oscillator differential input signal to generate an orthogonal differential signal; the limiting amplifier calibrates the amplitude and phase mismatch of the orthogonal differential signal to obtain a local oscillator orthogonal signal output.

[0010] In one embodiment of the present invention, the polyphase filter includes capacitors C1-C12 and resistors R1-R12;

[0011] The first ends of the capacitors C1, C2, C3, and C4 are connected to the first ends of the resistors R1, R2, R3, and R4, respectively, and the second ends of the capacitors C1, C2, C3, and C4 are connected to the second ends of the resistors R2, R3, R4, and R1, respectively; the first ends of the resistors R1 and R2 are interconnected, and the first ends of the resistors R3 and R4 are interconnected; the first ends of the capacitors C5, C6, C7, and C8 are connected to the first ends of the resistors R5, R6, R6, and R8, respectively, and the second ends of the capacitors C5, C6, C7, and C8 are connected to the second ends of the resistors R6, R7, R8, and R5, respectively; the first ends of the capacitors C9, C10, C11, and C12 are connected to the first ends of the resistors R9, R10, R11, and R12, respectively, and the second ends of the capacitors C9, C10, C11, and C12 are connected to the second ends of the resistors R10, R11, R12, and R9, respectively;

[0012] The first end of resistor R5 is connected to the second end of resistor R1, the first end of resistor R6 is connected to the second end of resistor R2, the first end of resistor R7 is connected to the second end of resistor R3, the first end of resistor R8 is connected to the second end of resistor R4, the first end of resistor R9 is connected to the second end of resistor R5, the first end of resistor R10 is connected to the second end of resistor R6, the first end of resistor R11 is connected to the second end of resistor R7, and the first end of resistor R12 is connected to the second end of resistor R8.

[0013] In one embodiment of the present invention, the limiting amplifier module includes transistors Q1 to Q16, resistors R13 to R26 and a capacitor C13;

[0014] The collectors of transistors Q1 and Q2 are connected to the second ends of resistors R14 and R15 respectively, the first ends of resistors R14 and R15 are connected to VDD through resistor R13, the emitters of transistors Q1 and Q2 are connected to the collector of transistor Q3; the base of transistor Q5 is connected to the collector of transistor Q1, and the emitter is connected to the collector of transistor Q7; the base of transistor Q6 is connected to the collector of transistor Q2, and the emitter is connected to the collector of transistor Q8;

[0015] The collectors of transistors Q5 and Q6 are connected to the emitter of transistor Q4, and the base and collector of transistor Q4 are connected to VDD; the bases of transistors Q3, Q7, and Q8 are connected to bias voltage VB1, and the emitters are connected to ground GND through resistors R16, R17, and R18 respectively; the base of transistor Q9 is connected to the emitter of transistor Q5, and the base of transistor Q10 is connected to the emitter of transistor Q6.

[0016] The collectors of transistors Q9 and Q10 are connected to the second ends of resistors R20 and R21 respectively, the first ends of resistors R20 and R21 are connected to VDD through resistor R19, the emitters of transistors Q9 and Q10 are connected to the collector of transistor Q11 through resistors R22 and R23 respectively, the two ends of capacitor C13 are connected to the emitters of transistors Q9 and Q10 respectively; the base of transistor Q13 is connected to the collector of transistor Q9, and the emitter is connected to the collector of transistor Q15; the base of transistor Q14 is connected to the collector of transistor Q10, and the emitter is connected to the collector of transistor Q16;

[0017] The collectors of transistors Q13 and Q14 are connected to the emitter of Q12, and the base and collector of Q12 are connected to VDD; the bases of transistors Q11, Q15, and Q16 are connected to the bias voltage VB2, and the emitters are connected to the ground GND through resistors R24, R25, and R26 respectively.

[0018] In one embodiment of the present invention, the mixer module adopts a Gilbert unit, including transistors Q17 to Q28, resistors R27 to R32, inductors L1 and L2, and capacitors C18 to C21;

[0019] The collectors of transistors Q17, Q19, Q21 and Q23 are connected to VDD through resistor R28 and inductor L2 in sequence; the collectors of transistors Q18, Q20, Q22 and Q24 are connected to VDD through resistor R27 and inductor L1 in sequence;

[0020] The bases of transistors Q17 and Q20 are interconnected, the bases of transistors Q18 and Q19 are interconnected, the bases of transistors Q21 and Q24 are interconnected, and the bases of transistors Q22 and Q23 are interconnected; the emitters of transistors Q17 and Q18 are both connected to the collector of transistor Q25, and the emitter of transistor Q25 is grounded to GND through resistor R29; the emitters of transistors Q19 and Q20 are both connected to the collector of transistor Q26, and the emitter of transistor Q26 is grounded to GND through resistor R30; the emitters of transistors Q21 and Q22 are both connected to the collector of transistor Q27, and the emitter of transistor Q27 is grounded to GND through resistor R31; the emitters of transistors Q23 and Q24 are both connected to the collector of transistor Q28, and the emitter of transistor Q28 is grounded to GND through resistor R32;

[0021] The base of the transistor Q25 is connected to GND via the capacitor C18, the base of the transistor Q26 is connected to GND via the capacitor C19, the base of the transistor Q27 is connected to GND via the capacitor C20, and the base of the transistor Q28 is connected to GND via the capacitor C21.

[0022] In one embodiment of the present invention, the differential-to-single-ended module includes transistors Q29-Q33, resistors R33-R38, capacitors C14-C17 and inductor L3;

[0023] The base of transistor Q29 is connected to the first end of capacitor C14 and resistor R34, the collector is connected to VDD, the emitter is connected to the collector of transistor Q33 through resistor R33 and inductor L3 in sequence, and the second end of resistor R34 is connected to VDD; the base of transistor Q30 is connected to the first end of capacitor C15 and resistor R35, the emitter is connected to GND through resistor R34, and the collector is connected to the emitter of transistor Q33; the second end of resistor R35 is connected to the emitter of transistor Q31, the first end of resistor R36, and the second end of resistor R37. The first end and the first end of the capacitor C16, the second end of the capacitor C16 are connected to GND, the second end of the resistor R36 is connected to the base of the transistor Q32, the base of the transistor Q31 is connected to the collector of the transistor Q32, the first end of the resistor R37, the base of the transistor Q33 and the first end of the capacitor C17, the second end of the capacitor C17 is connected to GND, the second end of the resistor R37 is connected to VDD, the collector of the transistor Q31 is connected to VDD, and the emitter of the transistor Q32 is connected to GND through the resistor R38.

[0024] In one embodiment of the present invention, the multi-phase filter generates four orthogonal differential signals with a phase difference of 90°.

[0025] The high-linearity broadband orthogonal modulator provided by the present invention includes a phase shifter module, a mixer module and a differential-to-single-ended module, which can achieve a broadband operating frequency of 50MHz to 6GHz. The phase shifter module shifts the phase of the local oscillator differential input signal to generate a local oscillator orthogonal signal output; the mixer module mixes and outputs the output signal of the phase shifter module and the baseband input signal; the differential-to-single-ended module converts the output differential signal of the mixer module into a single-ended signal and then outputs it. Compared with the traditional orthogonal modulator technology, the local oscillator orthogonal generation of the present invention adopts a multi-phase filter method, which is implemented by resistors and capacitors, has a smaller chip area, and can achieve ultra-wideband operation, covering the local oscillator input frequency range of 50MHz to 6GHz; the sideband suppression is about -50dBc, and the carrier leakage is about -40dBm, which can achieve excellent modulation performance within the broadband operating frequency range. The mixer module adopts inductor peaking, and the differential-to-single-ended module adopts a broadband active balun structure to achieve gain compensation and high linearity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of a high linearity broadband orthogonal modulator provided by the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the phase shifter module in the high linearity broadband orthogonal modulator;

[0028] Figure 3 is a circuit diagram of a polyphase filter in a phase shifter module;

[0029] Figure 4 is the circuit diagram of the limiting amplifier in the phase shifter module;

[0030] Figure 5 It is a circuit diagram of a mixer module in a high linearity broadband orthogonal modulator;

[0031] Figure 6 It is a circuit diagram of a differential-to-single-ended module in a high-linearity broadband orthogonal modulator. DETAILED DESCRIPTION

[0032] The following is a further detailed description of a high linearity broadband orthogonal modulator proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0033] The present invention provides a high linearity broadband orthogonal modulator, the structure of which is as follows: Figure 1 As shown, it includes a phase shifter module, a mixer module and a differential to single-ended module, which can achieve a 50MHz to 6GHz broadband operating frequency. The phase shifter module converts the local oscillator differential input signal LO P and LO N Phase shifting is performed to generate a local oscillator quadrature signal output; the mixer module combines the output signal of the phase shifter module and the baseband input signal BB IP BB IN BB QP BB QN The differential to single-ended module converts the output differential signal of the mixer module into a single-ended signal and then outputs the RF out .

[0034] The principle of the phase shifter module is as follows Figure 2 As shown, it includes a polyphase filter and two limiting amplifiers. Figure 3The multiphase filter includes capacitors C1 to C12 and resistors R1 to R12; the first ends of capacitors C1, C2, C3, and C4 are respectively connected to the first ends of resistors R1, R2, R3, and R4, and the second ends of capacitors C1, C2, C3, and C4 are respectively connected to the second ends of resistors R2, R3, R4, and R1; the first ends of resistors R1 and R2 are interconnected, and the first ends of resistors R3 and R4 are interconnected; the first ends of capacitors C5, C6, C7, and C8 are respectively connected to the first ends of resistors R2, R3, R4, and R1; The first ends of the capacitors C5, C6, C7, and C8 are connected to the second ends of the resistors R6, R7, R8, and R5 respectively; the first ends of the capacitors C9, C10, C11, and C12 are connected to the first ends of the resistors R9, R10, R11, and R12 respectively, and the second ends of the capacitors C9, C10, C11, and C12 are connected to the second ends of the resistors R10, R11, R12, and R9 respectively. In addition, the first end of the resistor R5 is connected to the second end of the resistor R1, the first end of the resistor R6 is connected to the second end of the resistor R2, the first end of the resistor R7 is connected to the second end of the resistor R3, the first end of the resistor R8 is connected to the second end of the resistor R4, the first end of the resistor R9 is connected to the second end of the resistor R5, the first end of the resistor R10 is connected to the second end of the resistor R6, the first end of the resistor R11 is connected to the second end of the resistor R7, and the first end of the resistor R12 is connected to the second end of the resistor R8. The results of the two limiting amplifiers are the same, please refer to Figure 4, each limiting amplifier includes transistors Q1-Q16, resistors R13-R26 and capacitor C13; the collectors of transistors Q1 and Q2 are connected to the second ends of resistors R14 and R15 respectively, the first ends of resistors R14 and R15 are connected to VDD through resistor R13, the emitters of transistors Q1 and Q2 are connected to the collector of transistor Q3; the base of transistor Q5 is connected to the collector of transistor Q1, and the emitter is connected to the collector of transistor Q7; The base of transistor Q6 is connected to the collector of transistor Q2, and the emitter is connected to the collector of transistor Q8; the collectors of transistors Q5 and Q6 are connected to the emitter of transistor Q4, and the base and collector of transistor Q4 are connected to VDD; the bases of transistors Q3, Q7, and Q8 are connected to bias voltage VB1, and the emitters are connected to ground GND through resistors R16, R17, and R18 respectively; the base of transistor Q9 is connected to the emitter of transistor Q5, and the base of transistor Q1 is connected to the emitter of transistor Q5. The base of transistor Q0 is connected to the emitter of transistor Q6, the collectors of transistors Q9 and Q10 are connected to the second ends of resistors R20 and R21 respectively, the first ends of resistors R20 and R21 are connected to VDD through resistor R19, the emitters of transistors Q9 and Q10 are connected to the collector of transistor Q11 through resistors R22 and R23 respectively, the two ends of capacitor C13 are connected to the emitters of transistors Q9 and Q10 respectively; the base of transistor Q13 is connected to the transistor The collector and emitter of transistor Q9 are connected to the collector of transistor Q15; the base of transistor Q14 is connected to the collector of transistor Q10, and the emitter is connected to the collector of transistor Q16; the collectors of transistors Q13 and Q14 are both connected to the emitter of Q12, and the base and collector of Q12 are connected to VDD; the bases of transistors Q11, Q15, and Q16 are all connected to the bias voltage VB2, and the emitters are connected to ground GND through resistors R24, R25, and R26 respectively.

[0035] The mixer module uses Gilbert cells, see Figure 5The mixer module includes transistors Q17-Q28, resistors R27-R32, inductors L1 and L2, and capacitors C18-C21; the collectors of transistors Q17, Q19, Q21, and Q23 are connected to VDD in sequence through resistor R28 and inductor L2; the collectors of transistors Q18, Q20, Q22, and Q24 are connected to VDD in sequence through resistor R27 and inductor L1; the bases of transistors Q17 and Q20 are interconnected, the bases of transistors Q18 and Q19 are interconnected, the bases of transistors Q21 and Q24 are interconnected, and the bases of transistors Q22 and Q23 are interconnected; the transistors The emitters of Q17 and Q18 are connected to the collector of transistor Q25, and the emitter of transistor Q25 is grounded to GND through resistor R29; the emitters of transistors Q19 and Q20 are connected to the collector of transistor Q26, and the emitter of transistor Q26 is grounded to GND through resistor R30; the emitters of transistors Q21 and Q22 are connected to the collector of transistor Q27, and the emitter of transistor Q27 is grounded to GND through resistor R31; the emitters of transistors Q23 and Q24 are connected to the collector of transistor Q28, and the emitter of transistor Q28 is grounded to GND through resistor R32. The base of transistor Q25 is connected to GND through capacitor C18, the base of transistor Q26 is connected to GND through capacitor C19, the base of transistor Q27 is connected to GND through capacitor C20, and the base of transistor Q28 is connected to GND through capacitor C21.

[0036] See also Figure 6 The differential-to-single-ended module includes transistors Q29-Q33, resistors R33-R38, capacitors C14-C17 and inductor L3; the base of transistor Q29 is connected to the first end of capacitor C14 and resistor R34, the collector is connected to VDD, the emitter is connected to the collector of transistor Q33 through resistor R33 and inductor L3 in sequence, and the second end of resistor R34 is connected to VDD; the base of transistor Q30 is connected to the first end of capacitor C15 and resistor R35, the emitter is connected to GND through resistor R34, and the collector is connected to the emitter of transistor Q33; resistor R35 The second end of is connected to the emitter of transistor Q31, the first end of resistor R36 and the first end of capacitor C16, the second end of capacitor C16 is connected to GND, the second end of resistor R36 is connected to the base of transistor Q32, the base of transistor Q31 is connected to the collector of transistor Q32, the first end of resistor R37, the base of transistor Q33 and the first end of capacitor C17, the second end of capacitor C17 is connected to GND, the second end of resistor R37 is connected to VDD, the collector of transistor Q31 is connected to VDD, and the emitter of transistor Q32 is connected to GND through resistor R38.

[0037] like Figure 2 As shown, the local oscillator differential input signal LO P and LON After phase shifting by a polyphase filter, four orthogonal differential signals IP, IN, QP and QN with a phase difference of 90° are generated; these four signals are calibrated for amplitude and phase mismatch of the orthogonal differential signals through a limiting amplifier to obtain the final local oscillator orthogonal signal LO IP ,LO IN ,LO QP ,LO QN As the input signal to the mixer switching stage.

[0038] like Figure 5 As shown, four orthogonal differential BB signals are input. IP BB IN BB QP BB QN As the baseband input signal of the mixer module. Resistors R29, R30, R31, and R32 are emitter negative feedback of transistors Q25, Q26, Q27, and Q28, respectively, which can effectively improve the linearity of the transconductance stage; the two ends of the output differential are connected by load resistors (i.e., resistors R27 and R28, inductors L1 and L2). The last stage differential to single-ended module adopts an active balun structure, such as Figure 6 The differential signal output by the mixer module is converted into a single-ended signal and then output.

[0039] The high linearity broadband orthogonal modulator of the present invention is designed and taped out using SiGe process. In this embodiment, the power supply voltage is 5V, covering an operating frequency range from 50MHz to 6GHz. At 2GHz, its output 1dB compression point is 14.7dBm, the output third-order intermodulation point is 24.5dBm, and the second-order intermodulation point is 73dBm, with excellent linearity performance. The local oscillator uses a multi-phase filter to achieve phase shifting, thereby achieving ultra-wideband operation. The sideband suppression is approximately -50dBc, and the carrier leakage is approximately -40dBm, which can achieve excellent modulation performance within the broadband operating frequency range. The mixer module uses inductor peaking, and the differential to single-ended module uses a broadband active balun structure to achieve gain compensation and high linearity, and can achieve a voltage gain of -0.9dB.

[0040] The high linearity broadband orthogonal modulator proposed in the present invention is suitable for the design of high performance orthogonal modulators with an operating frequency of 50MHz to 6GHz, and can achieve a compromise between broadband, high linearity and low error performance based on the existing mature SiGe process platform.

[0041] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A high linearity broadband orthogonal modulator, characterized in that: include: The phase shifter module performs phase shifting on the local oscillator differential input signal to generate a local oscillator quadrature signal output; A mixer module, mixing and outputting the output signal of the phase shifter module and the baseband input signal; A differential-to-single-ended module converts the output differential signal of the mixer module into a single-ended signal and then outputs it; The phase shifter module includes a polyphase filter and a limiting amplifier connected in sequence; the polyphase filter performs phase shifting on the local oscillator differential input signal to generate an orthogonal differential signal; the limiting amplifier calibrates the amplitude and phase mismatch of the orthogonal differential signal to obtain a local oscillator orthogonal signal output; The multi-phase filter includes capacitors C1-C12 and resistors R1-R12; The first ends of the capacitors C1, C2, C3, and C4 are connected to the first ends of the resistors R1, R2, R3, and R4, respectively, and the second ends of the capacitors C1, C2, C3, and C4 are connected to the second ends of the resistors R2, R3, R4, and R1, respectively; the first ends of the resistors R1 and R2 are interconnected, and the first ends of the resistors R3 and R4 are interconnected; the first ends of the capacitors C5, C6, C7, and C8 are connected to the first ends of the resistors R5, R6, R6, and R8, respectively, and the second ends of the capacitors C5, C6, C7, and C8 are connected to the second ends of the resistors R6, R7, R8, and R5, respectively; the first ends of the capacitors C9, C10, C11, and C12 are connected to the first ends of the resistors R9, R10, R11, and R12, respectively, and the second ends of the capacitors C9, C10, C11, and C12 are connected to the second ends of the resistors R10, R11, R12, and R9, respectively; A first end of the resistor R5 is connected to the second end of the resistor R1, a first end of the resistor R6 is connected to the second end of the resistor R2, a first end of the resistor R7 is connected to the second end of the resistor R3, a first end of the resistor R8 is connected to the second end of the resistor R4, a first end of the resistor R9 is connected to the second end of the resistor R5, a first end of the resistor R10 is connected to the second end of the resistor R6, a first end of the resistor R11 is connected to the second end of the resistor R7, and a first end of the resistor R12 is connected to the second end of the resistor R8; The limiting amplifier module includes transistors Q1-Q16, resistors R13-R26 and capacitor C13; The collectors of transistors Q1 and Q2 are connected to the second ends of resistors R14 and R15 respectively, the first ends of resistors R14 and R15 are connected to VDD through resistor R13, the emitters of transistors Q1 and Q2 are connected to the collector of transistor Q3; the base of transistor Q5 is connected to the collector of transistor Q1, and the emitter is connected to the collector of transistor Q7; the base of transistor Q6 is connected to the collector of transistor Q2, and the emitter is connected to the collector of transistor Q8; The collectors of transistors Q5 and Q6 are connected to the emitter of transistor Q4, and the base and collector of transistor Q4 are connected to VDD; the bases of transistors Q3, Q7, and Q8 are connected to bias voltage VB1, and the emitters are connected to ground GND through resistors R16, R17, and R18 respectively; the base of transistor Q9 is connected to the emitter of transistor Q5, and the base of transistor Q10 is connected to the emitter of transistor Q6. The collectors of transistors Q9 and Q10 are connected to the second ends of resistors R20 and R21 respectively, the first ends of resistors R20 and R21 are connected to VDD through resistor R19, the emitters of transistors Q9 and Q10 are connected to the collector of transistor Q11 through resistors R22 and R23 respectively, the two ends of capacitor C13 are connected to the emitters of transistors Q9 and Q10 respectively; the base of transistor Q13 is connected to the collector of transistor Q9, and the emitter is connected to the collector of transistor Q15; the base of transistor Q14 is connected to the collector of transistor Q10, and the emitter is connected to the collector of transistor Q16; The collectors of transistors Q13 and Q14 are connected to the emitter of Q12, and the base and collector of Q12 are connected to VDD; the bases of transistors Q11, Q15, and Q16 are connected to the bias voltage VB2, and the emitters are connected to the ground GND through resistors R24, R25, and R26 respectively; The mixer module adopts a Gilbert unit, including transistors Q17-Q28, resistors R27-R32, inductors L1 and L2, and capacitors C18-C21; The collectors of transistors Q17, Q19, Q21 and Q23 are connected to VDD through resistor R28 and inductor L2 in sequence; the collectors of transistors Q18, Q20, Q22 and Q24 are connected to VDD through resistor R27 and inductor L1 in sequence; The bases of transistors Q17 and Q20 are interconnected, the bases of transistors Q18 and Q19 are interconnected, the bases of transistors Q21 and Q24 are interconnected, and the bases of transistors Q22 and Q23 are interconnected; the emitters of transistors Q17 and Q18 are both connected to the collector of transistor Q25, and the emitter of transistor Q25 is grounded to GND through resistor R29; the emitters of transistors Q19 and Q20 are both connected to the collector of transistor Q26, and the emitter of transistor Q26 is grounded to GND through resistor R30; the emitters of transistors Q21 and Q22 are both connected to the collector of transistor Q27, and the emitter of transistor Q27 is grounded to GND through resistor R31; the emitters of transistors Q23 and Q24 are both connected to the collector of transistor Q28, and the emitter of transistor Q28 is grounded to GND through resistor R32; The base of transistor Q25 is connected to GND via capacitor C18, the base of transistor Q26 is connected to GND via capacitor C19, the base of transistor Q27 is connected to GND via capacitor C20, and the base of transistor Q28 is connected to GND via capacitor C21; The differential-to-single-ended module includes transistors Q29-Q33, resistors R33-R38, capacitors C14-C17 and inductor L3; The base of transistor Q29 is connected to the first end of capacitor C14 and resistor R34, the collector is connected to VDD, the emitter is connected to the collector of transistor Q33 through resistor R33 and inductor L3 in sequence, and the second end of resistor R34 is connected to VDD; the base of transistor Q30 is connected to the first end of capacitor C15 and resistor R35, the emitter is connected to GND through resistor R34, and the collector is connected to the emitter of transistor Q33; the second end of resistor R35 is connected to the emitter of transistor Q31, the first end of resistor R36, and the second end of resistor R37. The first end and the first end of the capacitor C16, the second end of the capacitor C16 are connected to GND, the second end of the resistor R36 is connected to the base of the transistor Q32, the base of the transistor Q31 is connected to the collector of the transistor Q32, the first end of the resistor R37, the base of the transistor Q33 and the first end of the capacitor C17, the second end of the capacitor C17 is connected to GND, the second end of the resistor R37 is connected to VDD, the collector of the transistor Q31 is connected to VDD, and the emitter of the transistor Q32 is connected to GND through the resistor R38.

2. The high linearity broadband orthogonal modulator according to claim 1, characterized in that: The multi-phase filter generates four orthogonal differential signals with a phase difference of 90°.

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