A broadband and high modulation accuracy RF quadrature modulator

Abstract

The present invention discloses a broadband high modulation precision radio frequency orthogonal modulator, which belongs to the field of integrated circuit signal processing, and includes an input amplifier, a high speed pre-divider, a limiting amplifier module, a pre-driving circuit, an active double balanced mixer and an output amplifier. The input amplifier converts the local oscillator input signal into a differential signal, amplifies and outputs it; the high speed pre-divider divides the local oscillator differential signal output by the input amplifier by two, generates an orthogonal differential signal and then outputs it; the limiting amplifier module performs limiting amplification and outputs the orthogonal differential signal output by the high speed pre-divider; the pre-driving circuit converts the baseband input voltage signal into a current signal and then outputs it; the active double balanced mixer mixes and outputs the signal output by the limiting amplifier module and the signal output by the pre-driving circuit; the output amplifier converts the output differential signal of the active double balanced mixer into a single-ended signal and outputs it. The present invention is suitable for the design of a high performance orthogonal modulator with a radio frequency output frequency of 30MHz to 2.2GHz.

Description

Technical Field

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

[0002] As science and technology become more mature, modern communication systems have achieved various technological breakthroughs, from the original analog modulation signal communication, narrowband voice communication, and wired transmission communication to the realization of digital modulation signal communication, broadband integrated service communication, and wireless mobile communication. Electronic communication systems are becoming more and more abundant. Communication systems are constantly developing towards large capacity and high speed, and the requirements for radio frequency communication technology are becoming more critical; radio frequency signals are extending to higher frequencies and larger ranges.

[0003] The realization of wireless communication system mainly relies on radio frequency communication circuit. After years of continuous research and accumulation, radio frequency communication system has basically formed a typical structure, which mainly includes modulation, frequency conversion, amplification and demodulation. In recent years, the application fields of radio frequency communication circuit mainly include aerospace communication, radar satellite communication, shipboard communication, personal mobile communication, wireless local area network, Internet of Things and Internet of Vehicles.

[0004] 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 and more demanding. 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, the modem is the most core module in the signal transceiver. The mixer can change the frequency of the output signal of the oscillation source, thereby realizing the modulation and demodulation of the signal. The orthogonal modulator is mainly used in the transmitter to modulate the baseband signal to the RF signal and then output it. Summary of the invention

[0005] The object of the present invention is to provide a broadband and high modulation precision radio frequency orthogonal modulator to solve the problems in the background technology.

[0006] In order to solve the above technical problems, the present invention provides a broadband and high modulation precision radio frequency orthogonal modulator, comprising:

[0007] Input amplifier, converts the local oscillator input signal into a differential signal, amplifies it and outputs it;

[0008] A high-speed pre-divider divides the local oscillator differential signal output by the input amplifier into two frequencies to generate an orthogonal differential signal for output;

[0009] A limiting amplifier module is used to perform limiting amplification and output on the orthogonal differential signal output by the high-speed pre-divider;

[0010] A pre-driver circuit converts the baseband input voltage signal into a current signal and then outputs it;

[0011] an active double-balanced mixer, mixing and outputting the signal output by the limiting amplifier module and the signal output by the pre-driving circuit;

[0012] An output amplifier, converting the output differential signal of the active double-balanced mixer into a single-ended signal output;

[0013] The bandgap reference module provides reference voltage for the above modules.

[0014] In one embodiment, the input amplifier includes transistors Q1 to Q9, resistors R1 to R10 and capacitor C5; wherein transistors Q1 and Q2 are used as amplifiers, resistors R7 and R8 are used as load resistors, transistors Q8, Q9 and resistors R1, R2, R3 are used to provide bias voltage for local oscillator input signals, and resistors R2 and R3 are also used for input matching; transistors Q4 and Q5 are used as emitter-follower buffer circuits;

[0015] The bases of transistors Q3, Q6 and Q7 are all connected to the bias voltage VB1, and the emitters are grounded through resistors R4, R5 and R6 respectively. The collector of transistor Q3 is connected to the emitter of transistor Q1 and the emitter of transistor Q2 at the same time, the collector of transistor Q6 is connected to the emitter of transistor Q4, and the collector of transistor Q7 is connected to the emitter of transistor Q5;

[0016] The collector of transistor Q1 and the collector of transistor Q2 are connected to the first end of resistor R9 through resistor R7 and resistor R8 respectively, and the second end of resistor R9 is connected to VDD; the base of transistor Q1 is connected to the first end of resistor R2, the base of transistor Q2 is connected to the first end of resistor R3, and the base of transistor Q2 is connected to GND outside the chip through capacitor C5; the base and collector of transistor Q8 are connected to the first end of resistor R9, the base and collector of transistor Q9 are connected to the emitter of transistor Q18, the emitter of transistor Q9 is connected to the first end of resistor R1, and the second end of resistor R1, the second end of resistor R2 and the second end of resistor R3 are interconnected;

[0017] The collector of transistor Q4 and the collector of transistor Q5 are both connected to the first end of resistor R10, and the second end of resistor R10 is connected to VDD; the base of transistor Q4 is connected to the collector of transistor Q1, and the emitter is connected to the collector of transistor Q6; the base of transistor Q5 is connected to the collector of transistor Q2, and the emitter is connected to the collector of transistor Q7.

[0018] In one embodiment, the high-speed prescaler module includes transistors Q10-Q31 and resistors R11-R23; wherein the transistors Q10-Q21 and resistors R11, R12, R19, R20 constitute two master-slave connected current-type latch circuits, and the transistors Q24-Q27 constitute an emitter-follower buffer stage circuit;

[0019] The base of the transistor Q10 is connected to the base of the transistor Q13, the base of the transistor Q11 is connected to the base of the transistor Q12, the emitter of the transistor Q10 and the emitter of the transistor Q11 are both connected to the collector of the transistor Q22, the emitter of the transistor Q12 and the emitter of the transistor Q13 are both connected to the collector of the transistor Q23; the collector of the transistor Q10 is connected to the emitter of the transistor Q14 and the emitter of the transistor Q15, the collector of the transistor Q11 is connected to the emitter of the transistor Q16 and the emitter of the transistor Q17, the collector of the transistor Q12 is connected to the emitter of the transistor Q18 and the emitter of the transistor Q19, and the collector of the transistor Q13 is connected to the emitter of the transistor Q20 and the emitter of the transistor Q21;

[0020] The base of transistor Q14 is connected to the collector of transistor Q19, the base of transistor Q15 is connected to the collector of transistor Q18, the base of transistor Q18 is connected to the collector of transistor Q14, and the base of transistor Q19 is connected to the collector of transistor Q15; the collector of transistor Q14, the collector of transistor Q15, the collector of transistor Q18 and the collector of transistor Q19 are connected to one end of resistors R11, R12, R19 and R20 respectively, and the other ends of resistors R11, R12, R19 and R20 are all connected to VDD through resistor R21;

[0021] The base of the transistor Q16 is connected to the collector of the transistor Q17 and the collector of the transistor Q15 at the same time, the base of the transistor Q17 is connected to the collector of the transistor Q16 and the collector of the transistor Q14, the base of the transistor Q20 is connected to the collector of the transistor Q21 and the collector of the transistor Q19, and the base of the transistor Q21 is connected to the collector of the transistor Q20 and the collector of the transistor Q18;

[0022] The base of transistor Q24 is connected to the collector of transistor Q15, and the emitter is connected to the collector of transistor Q28; the base of transistor Q25 is connected to the collector of transistor Q14, and the emitter is connected to the collector of transistor Q29; the base of transistor Q26 is connected to the collector of transistor Q19, and the emitter is connected to the collector of transistor Q30; the base of transistor Q27 is connected to the collector of transistor Q18, and the emitter is connected to the collector of transistor Q31; the collectors of transistors Q24 and Q25 are connected to VDD through resistor R22, and the collectors of transistors Q26 and Q27 are connected to VDD through resistor R23;

[0023] The bases of transistors Q22, Q23, Q28 to Q31 are all connected to the bias voltage VB2, and the emitters of transistors Q22, Q23, Q28 to Q31 are grounded through resistors R13, R14, R15, R16, R17 and R18 respectively.

[0024] In one embodiment, the pre-driving circuit includes transistors Q43 to Q46, resistors R28 to R31, and capacitors C1 and C2; wherein the resistor R28 and the capacitor C1, the resistor R29 and the capacitor C2 are used for filtering;

[0025] The base of transistor Q43 is connected to one end of resistor R28, and the other end of resistor R28 is connected to GND through capacitor C1; the base of transistor Q44 is connected to one end of resistor R29, and the other end of resistor R29 is connected to GND through capacitor C2; the collectors of transistors Q43 and Q44 are both connected to GND, the emitter of transistor Q43 is connected to the collector of transistor Q45, and the emitter of transistor Q44 is connected to the collector of transistor Q46; the emitter of transistor Q45 is connected to VDD through resistor R30, the emitter of transistor Q46 is connected to VDD through resistor R31, and the bases of transistors Q45 and Q46 are both connected to bias voltage VB4.

[0026] In one embodiment, the active double-balanced mixer includes transistors Q32-Q35, Q48-Q59, and resistors R32-R37; wherein the transistors Q48-Q51 and the resistors R32-R35 are transconductance stages of the active double-balanced mixer, the transistors Q52-Q59 are switch stages of the active double-balanced mixer, the resistors R36 and R37 are load resistors, and the transistors Q32-Q35 are current injection transistors for reducing noise and increasing gain;

[0027] The collectors of transistors Q52, Q54, Q56 and Q58 are connected to VDD through resistor R37; the collectors of transistors Q53, Q55, Q57 and Q59 are connected to VDD through resistor R36; the bases of transistors Q52 and Q55 are interconnected, the bases of transistors Q53 and Q54 are interconnected, the bases of transistors Q56 and Q59 are interconnected, and the bases of transistors Q57 and Q58 are interconnected;

[0028] The emitters of transistors Q32 to Q35 are all connected to VDD, the bases are all connected to the bias voltage VB3, the collector of transistor Q32 is connected to the emitter of transistor Q52 and the emitter of transistor Q53, the collector of transistor Q33 is connected to the emitter of transistor Q54 and the emitter of transistor Q55, the collector of transistor Q34 is connected to the emitter of transistor Q56 and the emitter of transistor Q57, and the collector of transistor Q35 is connected to the emitter of transistor Q58 and the emitter of transistor Q59;

[0029] The emitters of transistors Q52 and Q53 are both connected to the collector of transistor Q48, the emitters of transistors Q54 and Q55 are both connected to the collector of transistor Q49, the emitters of transistors Q56 and Q57 are both connected to the collector of transistor Q50, and the emitters of transistors Q58 and Q59 are both connected to the collector of transistor Q51; the emitters of transistors Q48, Q49, Q50, and Q51 are grounded GND through resistors R32, R33, R34, and R35, respectively.

[0030] In one embodiment, the output amplifier is an active balun structure, including transistors Q60-Q65, resistors R38-R45, and capacitors C3 and C4; transistors Q60 and Q61 are emitter-follower buffer circuits, capacitors C3 and C4 are DC-isolating capacitors, and the active balun structure is composed of transistors Q64, Q65 and resistors R44 and R45, which converts the differential signal into a single-ended signal and amplifies it for output;

[0031] The emitter of transistor Q60 is connected to the collector of transistor Q62 and the first end of resistor R40, the emitter of transistor Q61 is connected to the collector of transistor Q63 and the first end of resistor R41, and the collectors of transistors Q60 and Q61 are both connected to VDD; the emitters of transistors Q62 and Q63 are connected to GND through resistors R38 and R39 respectively, and the bases of transistors Q62 and Q63 are both connected to bias voltage VB6;

[0032] The second end of the resistor R40 is connected to the first end of the capacitor C3, the second end of the resistor R41 is connected to the first end of the capacitor C4, the second end of the capacitor C3 is connected to the base of the transistor Q64 and the first end of the resistor R42, the second end of the capacitor C4 is connected to the base of the transistor Q65 and the first end of the resistor R43; the second end of the resistor R42 is connected to VDD, and the second end of the resistor R43 is connected to the bias voltage VB5; the collector of the transistor Q64 is connected to VDD, the emitter is connected to the collector of the transistor Q65 through the resistor R44, and the emitter of the transistor Q65 is connected to GND through the resistor R45.

[0033] In one embodiment, the bandgap reference module includes transistors Q66 to Q86, resistors R46 to R57, and capacitor C6;

[0034] The emitters of transistors Q66 to Q69 are connected to the collector of transistor Q79 through resistors R46 to R49 respectively, and the emitter of transistor Q79 is connected to VDD; the bases of transistors Q66 to Q69 are interconnected, the collector and base of transistor Q66 are interconnected and connected to the collector of transistor Q86, the emitter of transistor Q86 is connected to the collector of transistor Q70, the base of transistor Q86 and the base of transistor Q70 are connected to the two ends of capacitor C6 respectively, the base of transistor Q86 is connected to the collector of transistor Q68, and the emitter of transistor Q70 is connected to GND through resistor R50;

[0035] The collector of transistor Q71 is connected to the collector of transistor Q67, the collector of transistor Q72 is connected to the collector of transistor Q68, the bases of transistors Q71 and Q72 are interconnected and connected to the collector of transistor Q75, the base and collector of transistor Q73 are interconnected and connected to the emitter of transistor Q71, the base and collector of transistor Q74 are interconnected and connected to the emitter of transistor Q72, the emitter of transistor Q73 is connected to the emitter of Q70, and the emitter of transistor Q74 is connected to GND;

[0036] The collector of transistor Q75 is connected to the collector of transistor Q69, the emitter is connected to GND, the base is interconnected with the collector and base of transistor Q77, and the emitter of transistor Q77 is connected to GND; the emitter of transistor Q76 is connected to VDD, the base and collector are interconnected and connected to the collector of transistor Q77 through resistor R51;

[0037] The collector of transistor Q78 is interconnected with the emitter of transistor Q70, the emitter is connected to GND via resistor R52, the base is connected to GND via resistor R54 and is connected to the base of transistor Q70 via resistor R53;

[0038] The emitters of transistors Q80 and Q85 are interconnected and connected to VDD through resistor R56, the base and collector of transistor Q80 are interconnected and connected to the bases of transistors Q81 and Q82, the base and collector of transistor Q81 are interconnected, the collector of transistor Q82 is interconnected to the base of transistor Q79, the base of transistor Q83 is interconnected to the emitter of transistor Q82 and the collector of transistor Q84, the base of transistor Q84 is interconnected to the emitter of transistor Q81 and the collector of transistor Q83, the emitter of transistor Q83 is connected to GND, and the emitter of transistor Q84 is connected to GND through resistor R55.

[0039] In the broadband high modulation precision RF orthogonal modulator provided by the present invention, the baseband signal can be modulated to a RF signal of 30MHz to 2.2GHz. The present invention has the functions of single-ended input of external local oscillator signal and single-ended output of RF signal, which can facilitate the design of high-frequency port matching and significantly reduce the complexity of board-level application. The local oscillator input frequency range covers 60MHz to 4.4GHz, and the RF output frequency range covers 30MHz to 2.2GHz; orthogonal differential local oscillator signals are generated on-chip, and the local oscillator orthogonal generation adopts a two-frequency division method, which can realize ultra-wideband operation, and the orthogonal amplitude and phase balance and carrier suppression performance are improved through shaping by a two-stage limiting amplifier module; the baseband signal is input into an active double-balanced mixer after the pre-driving circuit, which further enhances the port isolation, reduces the influence of carrier feedthrough, and can achieve a carrier feedthrough performance better than -40dBm. The present invention realizes broadband RF orthogonal modulation function, has high sideband suppression performance, can achieve sideband suppression performance better than -45dBc, and can meet the strict requirements of broadband wireless transceiver systems for modulation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of a broadband and high modulation precision radio frequency orthogonal modulator provided by the present invention;

[0041] Figure 2 It is a circuit diagram of an input amplifier in a broadband and high modulation precision radio frequency orthogonal modulator provided by the present invention;

[0042] Figure 3 It is a circuit diagram of a high-speed pre-divider in a broadband and high-modulation-precision radio frequency orthogonal modulator provided by the present invention;

[0043] Figure 4 It is a schematic diagram of a pre-driving circuit in a broadband and high modulation precision radio frequency orthogonal modulator provided by the present invention;

[0044] Figure 5 It is a circuit diagram of an active double-balanced mixer in a broadband and high-modulation-precision radio frequency orthogonal modulator provided by the present invention;

[0045] Figure 6 It is a circuit diagram of an output amplifier in a broadband and high modulation precision radio frequency orthogonal modulator provided by the present invention;

[0046] Figure 7 The invention provides a circuit diagram of a bandgap reference module in a broadband and high modulation precision radio frequency orthogonal modulator. DETAILED DESCRIPTION

[0047] The following is a further detailed description of a broadband high modulation accuracy RF 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 clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0048] The present invention provides a broadband high modulation precision radio frequency orthogonal modulator, the structure of which is as follows: Figure 1 As shown, the present invention includes an active double-balanced mixer, an input amplifier, a high-speed pre-divider, a limiting amplifier module, a pre-driving circuit, an output amplifier, and a bandgap reference module. The present invention can modulate a baseband signal into a radio frequency signal of 30MHz to 2.2GHz.

[0049] The first amplifier converts the local oscillator single-ended input signal INP into local oscillator differential signals OUTP and OUTN, amplifies them and outputs them to the high-speed pre-divider; the high-speed pre-divider divides the local oscillator differential signal by two, generates an orthogonal differential signal and then outputs it, wherein the generated orthogonal differential signals IP and IN are input to a limiting amplifier module, and the generated orthogonal differential signals QP and QN are input to another limiting amplifier module; the limiting amplifier module performs limiting amplification on the orthogonal differential signal after the two-frequency division and outputs it to the active double-balanced mixer; the pre-drive circuit converts the baseband input voltage signal into a current signal and then outputs it, The intermediate voltage signals INIP and ININ output current signals to the IBBP port and the IBBN port of the active double-balanced mixer through a pre-driving circuit, and the voltage signals INQP and INQN output current signals to the QBBP port and the QBBN port of the active double-balanced mixer through a pre-driving circuit; the active double-balanced mixer module mixes the current signal and the orthogonal differential signal after limiting amplification and outputs them to the output amplifier; the output amplifier converts the output differential signal of the active double-balanced mixer into a single-ended signal for output; and the bandgap reference module provides a reference voltage for the above modules.

[0050] The structure of the input amplifier is shown in Figure 2The local oscillator input signal generally selects single-ended input, the port INN is grounded outside the chip through the capacitor C5, and the port INP is connected to the local oscillator input signal. The local oscillator input signal is converted from single-ended to differential after passing through the input amplifier, forming two output signals OUTP and OUTN as two inputs of the subsequent high-speed pre-divider; the input amplifier includes transistors Q1~Q9, resistors R1~R10 and capacitor C5; transistors Q1 and Q2 are used as amplifiers, resistors R7 and R8 are used as load resistors, transistors Q8, Q9 and resistors R1, R2, R3 are used to provide bias voltage for the local oscillator input signal, and resistors R2 and R3 are also used for input matching; transistors Q4 and Q5 are used as emitter-follower buffer circuits; VB1 is a bias voltage provided by the bias module and is used to control the working current of the circuit.

[0051] The structure of the high speed prescaler Figure 3 As shown, it includes transistors Q10~Q31 and resistors R11~23. After the local oscillator differential signals OUTP and OUTN pass through the high-speed pre-divider, the frequency becomes half of the original, and four orthogonal differential signals with a phase difference of 90° are generated. After passing through the emitter-follower buffer stage, four signals IP, IN, QP, and QN are output as inputs of two limiting amplifier modules in the subsequent stage. The high-speed pre-divider is a current-type latch circuit with two master-slave connections, mainly composed of transistors Q10~Q21 and resistors R11, R12, R19, and R20; the emitter-follower buffer stage circuit is composed of transistors Q24~Q27, and VB2 is a bias voltage provided by the bias module for controlling the working current of the circuit.

[0052] The pre-driving circuit is as follows Figure 4 As shown, the baseband input voltage signal is converted into a current signal and then output as the transconductance input signal of the active double-balanced mixer; the pre-drive circuit includes transistors Q43-Q46, resistors R28-R31 and capacitors C1-C2. Resistors R28, R29 and capacitors C1, C2 are used for filtering, and VB4 is a bias voltage provided by the bias module to control the working current of the circuit.

[0053] The active double balanced mixer is as Figure 5As shown, it includes transistors Q32-35, Q48-Q59, and resistors R32-R37. The active double-balanced mixer is an orthogonal double-balanced mixer of the Gilbert unit, which mixes the current signals (IBBP, IBBN, QBBP, QBBN) and the orthogonal differential signals (ILOP, ILON, QLOP, QLON) to achieve the modulation function and generate two differential output signals VOUTP and VOUTN; transistors Q48-Q51 and resistors R32-R35 are the transconductance stage of the active double-balanced mixer, transistors Q52-Q59 are the switch stage of the active double-balanced mixer, resistors R36 and R37 are load resistors, transistors Q32-Q35 are current injection transistors for reducing noise and increasing gain, and VB3 is a bias voltage provided by a bias module for controlling the working current of the circuit.

[0054] The output amplifier is as Figure 6 As shown, it includes transistors Q60-Q65, resistors R38-R45 and capacitors C3-C4, which are an active balun structure, converting the differential output signal (VOUTP, VOUTN) of the active double-balanced mixer into a single-ended signal RFOUT as the output of the chip; transistors Q60 and Q61 are emitter-follower buffer circuits, capacitors C3 and C4 are DC-isolating capacitors, and the active balun is composed of transistors Q64, Q65 and resistors R44, R45, which convert the differential signal into a single-ended signal and amplify it for output, and VB5 and VB6 are bias voltages provided by the bias module for controlling the working current of the circuit.

[0055] The bias module is used as a high-precision bandgap reference module to provide bias voltage for other modules. Figure 7 , including transistors Q66~Q86, resistor R57 and capacitor C6. The bandgap reference module forms an IPTAT current with a positive temperature coefficient through proportional NPN transistors. At the same time, this connection form also serves as a startup circuit, eliminating the degenerate point of the circuit and avoiding the existence of the 0 state. Wherein IPTAT=4VT*ln(400) / 3R, where VT is the thermal voltage, and R in this embodiment refers to the resistance value of resistor R50; therefore, the reference current generated under normal operation of the transistor is only related to the different parallel numbers and resistances of the transistors, and has nothing to do with the power supply, and is a positive temperature coefficient current. The bandgap reference module is composed of NPN tubes with different proportional structures, and the negative temperature Vbe and the positive temperature △Vbe compensate each other to form a reference voltage VREF with a low temperature coefficient, thereby ensuring the temperature coefficient of the reference voltage VREF.

[0056] The broadband high modulation precision RF orthogonal modulator of the present invention is designed and taped out by SiGe process. In the present embodiment, the power supply voltage is 5V, the frequency range of the local oscillator input signal covers 60MHz~4.4GHz, and the frequency range of the RF output signal covers 30MHz~2.2GHz; orthogonal differential local oscillator signals are generated on chip, and the local oscillator orthogonal generation adopts a two-frequency division method, which can realize ultra-wideband operation, and the orthogonal amplitude and phase balance and carrier suppression performance are improved through shaping by a two-stage limiting amplifier module; the baseband input voltage signal is input into the active double-balanced mixer after the pre-driving circuit, which further enhances the port isolation, reduces the influence of carrier feedthrough, and can achieve a carrier feedthrough performance better than -40dBm. The present invention realizes broadband RF orthogonal modulation function, has high sideband suppression performance, can achieve sideband suppression performance better than -45dBc, and can meet the strict requirements of broadband wireless transceiver system for modulation accuracy.

[0057] The broadband and high modulation precision RF orthogonal modulator proposed in the present invention is suitable for the design of high-performance orthogonal modulators with RF output frequencies of 30MHz to 2.2GHz, and can achieve a compromise between broadband, high precision, low power consumption, and low chip area performance based on the existing mature SiGe process platform.

[0058] 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 broadband high modulation precision radio frequency orthogonal modulator, characterized in that: include: Input amplifier, converts the local oscillator input signal into a differential signal, amplifies it and outputs it; A high-speed pre-divider divides the local oscillator differential signal output by the input amplifier into two frequencies to generate an orthogonal differential signal for output; A limiting amplifier module is used to perform limiting amplification and output on the orthogonal differential signal output by the high-speed pre-divider; A pre-driver circuit converts the baseband input voltage signal into a current signal and then outputs it; an active double-balanced mixer, mixing and outputting the signal output by the limiting amplifier module and the signal output by the pre-driving circuit; An output amplifier, converting the output differential signal of the active double-balanced mixer into a single-ended signal output; The bandgap reference module provides reference voltage for the above modules.

2. The broadband high modulation precision RF orthogonal modulator according to claim 1, characterized in that: The input amplifier includes transistors Q1-Q9, resistors R1-R10 and capacitor C5; wherein transistors Q1 and Q2 are used as amplifiers, resistors R7 and R8 are used as load resistors, transistors Q8, Q9 and resistors R1, R2, R3 are used to provide bias voltage for the local oscillator input signal, and resistors R2 and R3 are also used for input matching; transistors Q4 and Q5 are used as emitter-follower buffer circuits; The bases of transistors Q3, Q6 and Q7 are all connected to the bias voltage VB1, and the emitters are grounded through resistors R4, R5 and R6 respectively. The collector of transistor Q3 is connected to the emitter of transistor Q1 and the emitter of transistor Q2 at the same time, the collector of transistor Q6 is connected to the emitter of transistor Q4, and the collector of transistor Q7 is connected to the emitter of transistor Q5; The collector of transistor Q1 and the collector of transistor Q2 are connected to the first end of resistor R9 through resistor R7 and resistor R8 respectively, and the second end of resistor R9 is connected to VDD; the base of transistor Q1 is connected to the first end of resistor R2, the base of transistor Q2 is connected to the first end of resistor R3, and the base of transistor Q2 is connected to GND outside the chip through capacitor C5; the base and collector of transistor Q8 are connected to the first end of resistor R9, the base and collector of transistor Q9 are connected to the emitter of transistor Q18, the emitter of transistor Q9 is connected to the first end of resistor R1, and the second end of resistor R1, the second end of resistor R2 and the second end of resistor R3 are interconnected; The collector of transistor Q4 and the collector of transistor Q5 are both connected to the first end of resistor R10, and the second end of resistor R10 is connected to VDD; the base of transistor Q4 is connected to the collector of transistor Q1, and the emitter is connected to the collector of transistor Q6; the base of transistor Q5 is connected to the collector of transistor Q2, and the emitter is connected to the collector of transistor Q7.

3. The broadband high modulation precision RF orthogonal modulator according to claim 2, characterized in that: The high-speed pre-divider module includes transistors Q10-Q31 and resistors R11-R23; wherein the transistors Q10-Q21 and resistors R11, R12, R19, R20 form two master-slave connected current-type latch circuits, and the transistors Q24-Q27 form an emitter-follower buffer stage circuit; The base of the transistor Q10 is connected to the base of the transistor Q13, the base of the transistor Q11 is connected to the base of the transistor Q12, the emitter of the transistor Q10 and the emitter of the transistor Q11 are both connected to the collector of the transistor Q22, the emitter of the transistor Q12 and the emitter of the transistor Q13 are both connected to the collector of the transistor Q23; the collector of the transistor Q10 is connected to the emitter of the transistor Q14 and the emitter of the transistor Q15, the collector of the transistor Q11 is connected to the emitter of the transistor Q16 and the emitter of the transistor Q17, the collector of the transistor Q12 is connected to the emitter of the transistor Q18 and the emitter of the transistor Q19, and the collector of the transistor Q13 is connected to the emitter of the transistor Q20 and the emitter of the transistor Q21; The base of transistor Q14 is connected to the collector of transistor Q19, the base of transistor Q15 is connected to the collector of transistor Q18, the base of transistor Q18 is connected to the collector of transistor Q14, and the base of transistor Q19 is connected to the collector of transistor Q15; the collector of transistor Q14, the collector of transistor Q15, the collector of transistor Q18 and the collector of transistor Q19 are connected to one end of resistors R11, R12, R19 and R20 respectively, and the other ends of resistors R11, R12, R19 and R20 are all connected to VDD through resistor R21; The base of the transistor Q16 is connected to the collector of the transistor Q17 and the collector of the transistor Q15 at the same time, the base of the transistor Q17 is connected to the collector of the transistor Q16 and the collector of the transistor Q14, the base of the transistor Q20 is connected to the collector of the transistor Q21 and the collector of the transistor Q19, and the base of the transistor Q21 is connected to the collector of the transistor Q20 and the collector of the transistor Q18; The base of transistor Q24 is connected to the collector of transistor Q15, and the emitter is connected to the collector of transistor Q28; the base of transistor Q25 is connected to the collector of transistor Q14, and the emitter is connected to the collector of transistor Q29; the base of transistor Q26 is connected to the collector of transistor Q19, and the emitter is connected to the collector of transistor Q30; the base of transistor Q27 is connected to the collector of transistor Q18, and the emitter is connected to the collector of transistor Q31; the collectors of transistors Q24 and Q25 are connected to VDD through resistor R22, and the collectors of transistors Q26 and Q27 are connected to VDD through resistor R23; The bases of transistors Q22, Q23, Q28 to Q31 are all connected to the bias voltage VB2, and the emitters of transistors Q22, Q23, Q28 to Q31 are grounded through resistors R13, R14, R15, R16, R17 and R18 respectively.

4. The broadband high modulation precision RF orthogonal modulator according to claim 3, characterized in that: The pre-driving circuit includes transistors Q43-Q46, resistors R28-R31 and capacitors C1 and C2; wherein the resistor R28 and the capacitor C1, the resistor R29 and the capacitor C2 are used for filtering; The base of transistor Q43 is connected to one end of resistor R28, and the other end of resistor R28 is connected to GND through capacitor C1; the base of transistor Q44 is connected to one end of resistor R29, and the other end of resistor R29 is connected to GND through capacitor C2; the collectors of transistors Q43 and Q44 are both connected to GND, the emitter of transistor Q43 is connected to the collector of transistor Q45, and the emitter of transistor Q44 is connected to the collector of transistor Q46; the emitter of transistor Q45 is connected to VDD through resistor R30, the emitter of transistor Q46 is connected to VDD through resistor R31, and the bases of transistors Q45 and Q46 are both connected to bias voltage VB4.

5. The broadband high modulation precision RF orthogonal modulator according to claim 4, characterized in that: The active double-balanced mixer includes transistors Q32-Q35, Q48-Q59, and resistors R32-R37; wherein the transistors Q48-Q51 and the resistors R32-R35 are transconductance stages of the active double-balanced mixer, the transistors Q52-Q59 are switch stages of the active double-balanced mixer, the resistors R36 and R37 are load resistors, and the transistors Q32-Q35 are current injection transistors for reducing noise and increasing gain; The collectors of transistors Q52, Q54, Q56 and Q58 are connected to VDD via resistor R37; The collectors of transistors Q53, Q55, Q57 and Q59 are connected to VDD through resistor R36; the bases of transistors Q52 and Q55 are interconnected, the bases of transistors Q53 and Q54 are interconnected, the bases of transistors Q56 and Q59 are interconnected, and the bases of transistors Q57 and Q58 are interconnected; The emitters of transistors Q32 to Q35 are all connected to VDD, the bases are all connected to the bias voltage VB3, the collector of transistor Q32 is connected to the emitter of transistor Q52 and the emitter of transistor Q53, the collector of transistor Q33 is connected to the emitter of transistor Q54 and the emitter of transistor Q55, the collector of transistor Q34 is connected to the emitter of transistor Q56 and the emitter of transistor Q57, and the collector of transistor Q35 is connected to the emitter of transistor Q58 and the emitter of transistor Q59; The emitters of transistors Q52 and Q53 are both connected to the collector of transistor Q48, the emitters of transistors Q54 and Q55 are both connected to the collector of transistor Q49, the emitters of transistors Q56 and Q57 are both connected to the collector of transistor Q50, and the emitters of transistors Q58 and Q59 are both connected to the collector of transistor Q51; the emitters of transistors Q48, Q49, Q50, and Q51 are grounded GND through resistors R32, R33, R34, and R35, respectively.

6. The broadband high modulation precision RF orthogonal modulator according to claim 5, characterized in that: The output amplifier is an active balun structure, including transistors Q60-Q65, resistors R38-R45, and capacitors C3 and C4; transistors Q60 and Q61 are emitter-follower buffer circuits, capacitors C3 and C4 are DC-isolating capacitors, and the active balun structure is composed of transistors Q64, Q65 and resistors R44 and R45, which converts the differential signal into a single-ended signal and amplifies it for output; The emitter of transistor Q60 is connected to the collector of transistor Q62 and the first end of resistor R40, the emitter of transistor Q61 is connected to the collector of transistor Q63 and the first end of resistor R41, and the collectors of transistors Q60 and Q61 are both connected to VDD; the emitters of transistors Q62 and Q63 are connected to GND through resistors R38 and R39 respectively, and the bases of transistors Q62 and Q63 are both connected to bias voltage VB6; The second end of the resistor R40 is connected to the first end of the capacitor C3, the second end of the resistor R41 is connected to the first end of the capacitor C4, the second end of the capacitor C3 is connected to the base of the transistor Q64 and the first end of the resistor R42, the second end of the capacitor C4 is connected to the base of the transistor Q65 and the first end of the resistor R43; the second end of the resistor R42 is connected to VDD, and the second end of the resistor R43 is connected to the bias voltage VB5; the collector of the transistor Q64 is connected to VDD, the emitter is connected to the collector of the transistor Q65 through the resistor R44, and the emitter of the transistor Q65 is connected to GND through the resistor R45.

7. The broadband high modulation precision RF orthogonal modulator according to claim 6, characterized in that: The bandgap reference module includes transistors Q66 to Q86, resistors R46 to R57 and capacitor C6; The emitters of transistors Q66 to Q69 are connected to the collector of transistor Q79 through resistors R46 to R49 respectively, and the emitter of transistor Q79 is connected to VDD; the bases of transistors Q66 to Q69 are interconnected, the collector and base of transistor Q66 are interconnected and connected to the collector of transistor Q86, the emitter of transistor Q86 is connected to the collector of transistor Q70, the base of transistor Q86 and the base of transistor Q70 are connected to the two ends of capacitor C6 respectively, the base of transistor Q86 is connected to the collector of transistor Q68, and the emitter of transistor Q70 is connected to GND through resistor R50; The collector of transistor Q71 is connected to the collector of transistor Q67, the collector of transistor Q72 is connected to the collector of transistor Q68, the bases of transistors Q71 and Q72 are interconnected and connected to the collector of transistor Q75, the base and collector of transistor Q73 are interconnected and connected to the emitter of transistor Q71, the base and collector of transistor Q74 are interconnected and connected to the emitter of transistor Q72, the emitter of transistor Q73 is connected to the emitter of Q70, and the emitter of transistor Q74 is connected to GND; The collector of transistor Q75 is connected to the collector of transistor Q69, the emitter is connected to GND, the base is interconnected with the collector and base of transistor Q77, and the emitter of transistor Q77 is connected to GND; the emitter of transistor Q76 is connected to VDD, the base and collector are interconnected and connected to the collector of transistor Q77 through resistor R51; The collector of transistor Q78 is interconnected with the emitter of transistor Q70, the emitter is connected to GND via resistor R52, the base is connected to GND via resistor R54 and is connected to the base of transistor Q70 via resistor R53; The emitters of transistors Q80 and Q85 are interconnected and connected to VDD through resistor R56, the base and collector of transistor Q80 are interconnected and connected to the bases of transistors Q81 and Q82, the base and collector of transistor Q81 are interconnected, the collector of transistor Q82 is interconnected to the base of transistor Q79, the base of transistor Q83 is interconnected to the emitter of transistor Q82 and the collector of transistor Q84, the base of transistor Q84 is interconnected to the emitter of transistor Q81 and the collector of transistor Q83, the emitter of transistor Q83 is connected to GND, and the emitter of transistor Q84 is connected to GND through resistor R55.

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