A mixer circuit

Abstract

The invention discloses a mixer circuit, comprising: a diode mixer and a triode mixer, wherein a first intermediate frequency signal pair output by the diode mixer is input into the triode mixer, wherein the triode mixer comprises a first triode mixer and a second triode mixer which are electrically connected, and wherein the triode mixer comprises: a radio frequency input stage for amplifying an input signal, wherein the first intermediate frequency signal pair output by a first intermediate frequency port is input into the radio frequency input stage; a local oscillator frequency conversion stage, wherein the first intermediate frequency signal pair input into the triode mixer is processed into a second intermediate frequency signal pair using a second local oscillator signal pair; and an output load stage for converting the second intermediate frequency signal pair into a voltage signal and outputting the voltage signal, wherein the linearity and noise performance of the entire mixer circuit can be improved, the application scenario with high signal quality requirements can be processed, the operating frequency range of the entire mixer system can be expanded, and the signal strength and the dynamic range of the entire mixer system can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency circuits, and in particular relates to a mixer circuit. Background Art

[0002] A mixer is a circuit whose output signal frequency is equal to the sum, difference or other combination of the two input signal frequencies. It is widely used in the field of integrated circuit technology. A mixer is usually composed of nonlinear elements and a frequency selection circuit. The mixer is located after the low-noise amplifier and directly processes the RF signal amplified by the low-noise amplifier to achieve the mixing function. The mixer also needs to receive the local oscillator signal from the voltage-controlled oscillator. The transistor mixer is a circuit that uses the nonlinear characteristics of the transistor to complete the mixing function. Most traditional mixer circuits have poor linearity, especially when large signals are input, which will cause large distortion of the mixed output signal; the noise performance is also relatively poor, the noise coefficient of the transistor itself is high, and the DC bias circuit may introduce additional noise. The diode mixer is an electronic circuit that uses the nonlinear characteristics of the diode to achieve frequency conversion. The diode mixer has low frequency conversion gain and has no amplification effect. At the same time, the operating frequency range is limited, resulting in a small range of application scenarios. Summary of the invention

[0003] In order to solve the above problems existing in the prior art, the present application provides a mixer circuit to overcome the above deficiencies existing in the prior art.

[0004] The present invention adopts the following technical solutions:

[0005] A mixer circuit comprising:

[0006] A diode mixer, specifically comprising: a first balun, a second balun, and a first diode, a second diode, a third diode, and a fourth diode connected end to end in sequence, wherein the first balun is connected to a first end of the first diode and a second end of the fourth diode, the first balun is connected to a second end of the second diode and a first end of the third diode, the first balun is connected to a first radio frequency port and a first intermediate frequency port provided on the diode mixer, the second balun is connected to a second end of the first diode and a first end of the second diode, the second balun is connected to a second end of the third diode and a first end of the fourth diode, and the second balun is connected to a first local oscillator port provided on the diode mixer;

[0007] The triode mixer specifically comprises: a first triode mixer and a second triode mixer, wherein the first triode mixer is electrically connected to the second triode mixer, and the first triode mixer and the second triode mixer both comprise:

[0008] A radio frequency input stage, used for amplifying an input signal, wherein the first intermediate frequency signal pair output by the first intermediate frequency port is input to the radio frequency input stage;

[0009] A local oscillator frequency conversion stage, using a second local oscillator signal pair to process the first intermediate frequency signal pair input to the triode mixer into a second intermediate frequency signal pair;

[0010] The output load stage is used to convert the second intermediate frequency signal pair into a voltage signal and output it.

[0011] Through the above design, signal conversion and matching are effectively realized. The balanced architecture composed of four diodes effectively suppresses the mutual interference between the local oscillator signal and the radio frequency signal, as well as the odd harmonics and intermodulation products generated during the mixing process, greatly improving the linearity and signal quality of the mixer, reducing signal distortion and noise interference, and making the output intermediate frequency signal purer, so as to facilitate the secondary processing of the subsequent triode mixer. The triode mixer amplifies the strength of the input first intermediate frequency signal, providing a better foundation for the subsequent local oscillator frequency conversion stage processing, and helping to improve the stability and reliability of the entire mixing process. By selecting the second local oscillator signal of different frequencies, the frequency of the output signal can be flexibly adjusted to meet the needs of different communication systems or signal processing. This frequency conversion function is very important in applications such as multi-band communications and radar systems, and can realize the processing and conversion of signals of different frequencies. The secondary mixing can further improve the selectivity and anti-interference ability of the signal, effectively suppress the interference of the image frequency and other stray signals, and improve the purity and quality of the output signal.

[0012] Preferably, the first triode mixer specifically includes: a first triode, a second triode, a third triode, a fourth triode, a fifth triode and a sixth triode, the emitters of the first triode and the second triode are connected and connected to the collector of the fifth triode, the collector of the first triode is connected to the collector of the third triode and connected to the output load stage of the first triode mixer, the collector of the second triode is connected to the collector of the fourth triode and connected to the output load stage of the first triode mixer, the emitters of the third triode and the fourth triode are connected and connected to the collector of the sixth triode, the bases of the fifth triode and the sixth triode are both connected to the first intermediate frequency port, and the fifth triode and the sixth triode are both electrically connected to the second triode mixer. The secondary processing process can make more precise adjustments and optimizations to the signal, and can better adapt to signals of different frequencies and amplitudes compared to simple primary processing, and further improve the processing accuracy and stability of the mixer.

[0013] Further preferably, the second triode mixer specifically includes: a seventh triode, an eighth triode, a ninth triode, a tenth triode, an eleventh triode and a twelfth triode, the emitters of the seventh triode and the eighth triode are connected and connected to the collector of the eleventh triode, the collector of the seventh triode is connected to the collector of the ninth triode and connected to the output load stage of the second triode mixer, the collector of the eighth triode is connected to the collector of the tenth triode and connected to the output load stage of the second triode mixer, the emitters of the ninth triode and the tenth triode are connected and connected to the collector of the twelfth triode, the bases of the eleventh triode and the twelfth triode are both connected to the first intermediate frequency port, and the eleventh triode and the twelfth triode are both electrically connected to the first triode mixer. Two connected triode mixers can accurately control the amplitude and phase of the in-phase and quadrature signals respectively, which is beneficial for application in scenarios requiring precise phase and amplitude control and has a certain noise suppression capability.

[0014] Further preferably, the first transistor mixer further includes a fifth resistor and a sixth resistor, the second transistor mixer further includes a seventh resistor and an eighth resistor, one end of the fifth resistor is connected to the emitter of the fifth transistor, the other end of the fifth resistor is connected to the other end of the eighth resistor, one end of the sixth resistor is connected to the emitter of the sixth transistor, the other end of the sixth resistor is connected to the other end of the seventh resistor, one end of the seventh resistor is connected to the emitter of the eleventh transistor, and one end of the eighth resistor is connected to the emitter of the twelfth transistor. The fifth resistor, the sixth resistor, the seventh resistor and the eighth resistor are used as feedback resistors to improve linearity, make the working state of the transistor more stable, reduce signal distortion, provide a stable DC bias for the transistor, and reduce performance degradation and signal distortion caused by operating point drift.

[0015] Further preferably, a first inductor is further included, one end of which is connected to the other end of the sixth resistor and the other end of the seventh resistor, and the other end of which is connected to the other end of the fifth resistor and the other end of the eighth resistor. The first inductor can reduce noise and increase signal linearity in the process of converting voltage into current, and is used by the first triode mixer and the second triode mixer to reduce the circuit usage area, which is conducive to the miniaturization of the mixer circuit system.

[0016] Further preferably, the first transistor mixer further includes a first resistor and a second resistor, one end of the first resistor is connected to one end of the second resistor, the other end of the first resistor is connected to the collector of the first transistor, and the other end of the second resistor is connected to the collector of the fourth transistor. The first resistor and the second resistor can stabilize the output voltage, control the output current, and achieve signal matching.

[0017] Further preferably, the second triode mixer further includes a third resistor and a fourth resistor, one end of the third resistor is connected to one end of the fourth resistor, the other end of the third resistor is connected to the collector of the seventh triode, and the other end of the fourth resistor is connected to the collector of the tenth triode. The third resistor and the fourth resistor can stabilize the output voltage, control the output current, and achieve signal matching.

[0018] Further preferably, the second local oscillator signal pair includes an in-phase local oscillator signal pair and an orthogonal local oscillator signal pair, the in-phase local oscillator signal pair is input from the connection point between the base of the first transistor and the base of the fourth transistor, and the connection point between the base of the second transistor and the base of the third transistor, the orthogonal local oscillator signal pair is input from the connection point between the base of the seventh transistor and the base of the tenth transistor, and the connection point between the base of the eighth transistor and the base of the ninth transistor, and the first intermediate frequency signal pair is input from the connection point between the base of the fifth transistor and the base of the twelfth transistor, and the connection point between the base of the sixth transistor and the base of the eleventh transistor.

[0019] Further preferably, the second intermediate frequency signal pair includes an in-phase intermediate frequency signal pair and an orthogonal intermediate frequency signal pair, the in-phase intermediate frequency signal pair is output from the connection point between the collector of the first transistor and the other end of the first resistor, and the connection point between the collector of the fourth transistor and the other end of the second resistor, and the orthogonal intermediate frequency signal pair is output from the connection point between the collector of the seventh transistor and the other end of the third resistor, and the connection point between the collector of the tenth transistor and the other end of the fourth resistor.

[0020] Compared with the prior art, the beneficial results of the present invention are:

[0021] The present invention provides a mixer circuit, which utilizes a diode mixer to perform preliminary mixing on an input radio frequency signal, and provides a subsequent triode mixer with an input signal with relatively high linearity and low noise, and then utilizes the signal amplification capability of the triode mixer to improve the signal strength, reduce the need for additional amplifiers, improve the signal quality, and expand the operating frequency range of the mixing system. It can handle various input conditions ranging from weak signals to larger signal amplitude changes, and can maintain good performance under different signal strengths, thereby enhancing the adaptability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings provide further description of the embodiments, and the accompanying drawings are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present invention. It will be easy to recognize other embodiments and many expected advantages of the embodiments, as they become better understood by reference to the following detailed description. Other features, objects and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments made with reference to the following drawings:

[0023] Figure 1 is a circuit diagram of a mixer circuit according to a specific embodiment of the present invention.

[0024] The meaning of the numbers in the figure are: D1-first diode; D2-second diode; D3-third diode; D4-fourth diode; K1-first triode; K2-second triode; K3-third triode; K4-fourth triode; K5-fifth triode; K6-sixth triode; K7-seventh triode; K8-eighth triode; K9-ninth triode; K10-tenth triode; K11-eleventh triode; K12-twelfth triode; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5-fifth resistor; R6-sixth resistor; R7-seventh resistor; R8-eighth resistor; L1-first inductor. DETAILED DESCRIPTION

[0025] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0026] In the description of the present invention, it should be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] To facilitate understanding by those skilled in the art, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0029] Figure 1 A circuit diagram of a mixer circuit according to a specific embodiment of the present application is shown. Figure 1 As shown, it includes: a diode mixer for performing preliminary mixing processing and a triode mixer for performing secondary mixing processing, wherein the diode mixer specifically includes: a first balun, a second balun, and a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4 connected end to end in sequence, and specifically, the connection mode is that the second end of the first diode D1 is connected to the first end of the second diode D2, the second end of the second diode D2 is connected to the first end of the third diode D3, the second end of the third diode D3 is connected to the first end of the fourth diode D4, and the second end of the fourth diode D4 is connected to the first end of the first diode D1, forming a ring structure, and combining the connection mode of the first balun and the second balun, the basic architecture of the balanced mixer is formed, which effectively suppresses the mutual interference between the local oscillator signal and the radio frequency signal, as well as the odd harmonics and intermodulation products generated in the mixing process, improves the linearity and signal quality of the mixer, reduces signal distortion and noise interference, and makes the output intermediate frequency signal purer.

[0030] In a specific embodiment, the first balun is connected to the first end of the first diode D1 and the second end of the fourth diode D4, the first balun is connected to the second end of the second diode D2 and the first end of the third diode D3, the first balun is connected to the first radio frequency port DR and the first intermediate frequency port DT provided on the diode mixer, the second balun is connected to the second end of the first diode D1 and the first end of the second diode D2, the second balun is connected to the second end of the third diode D3 and the first end of the fourth diode D4, the second balun is connected to the first local oscillator port DL provided on the diode mixer, the local oscillator signal of the diode mixer is input into the mixer circuit of the present application from the first local oscillator port DL, the radio frequency signal to be processed is input from the first radio frequency port DR, after mixing processing, the first intermediate frequency signal pair is output from the first intermediate frequency port DT, and the first intermediate frequency signal pair is input into the triode mixer as the radio frequency signal pair AR+ and AR- of the triode mixer for further mixing processing.

[0031] In a specific embodiment, the triode mixer includes a first triode mixer for in-phase signal processing and a second triode mixer for orthogonal signal processing, wherein the first triode mixer specifically includes: a first triode K1, a second triode K2, a third triode K3, a fourth triode K4, a fifth triode K5, a sixth triode K6, a first resistor R1, a second resistor R2, a fifth resistor R5 and a sixth resistor R6;

[0032] The emitters of the first transistor K1 and the second transistor K2 are connected and connected to the collector of the fifth transistor K5. The collector of the first transistor K1 is connected to the collector of the third transistor K3 and the other end of the first resistor R1. One end of the first resistor R1 is connected to one end of the second resistor R2 and the power supply voltage VCC. The other end of the second resistor R2 is connected to the collector of the fourth transistor K4 and the collector of the second transistor K2. In the first transistor mixer, the local oscillator frequency conversion stage includes the first transistor K1, the second transistor K2, the third transistor K3 and the fourth transistor K4, and processes the first intermediate frequency signal pair input to the transistor mixer into a second intermediate frequency signal pair. In the first transistor mixer, the output load stage includes the relevant parts of the first resistor R1 and the second resistor R2, which are used to convert the second intermediate frequency signal pair into a voltage signal and output it.

[0033] In a specific embodiment, the second triode mixer specifically includes: the second triode mixer specifically includes: a seventh triode K7, an eighth triode K8, a ninth triode K9, a tenth triode K10, an eleventh triode K11, a twelfth triode K12, a seventh resistor R7, an eighth resistor R8, a third resistor R3 and a fourth resistor R4;

[0034] The emitters of the seventh triode K7 and the eighth triode K8 are connected to each other and to the collector of the eleventh triode K11. The collector of the seventh triode K7 is connected to the collector of the ninth triode K9 and the other end of the third resistor R3. One end of the third resistor R3 is connected to one end of the fourth resistor R4 and the power supply voltage VCC. The other end of the fourth resistor R4 is connected to the collector of the eighth triode K8 and the collector of the eleventh triode K10. The ninth triode K9 and the eleventh triode K 10 is connected to the emitter of the twelfth transistor K12, and is connected to the collector of the twelfth transistor K12. In the second transistor mixer, the local oscillator frequency conversion stage includes a seventh transistor K7, an eighth transistor K8, a ninth transistor K9 and a tenth transistor K10, which process the first intermediate frequency signal pair input into the transistor mixer into a second intermediate frequency signal pair. In the second transistor mixer, the output load stage includes a third resistor R3 and a relevant part of a fourth resistor R4, which is used to convert the second intermediate frequency signal pair into a voltage signal and output it.

[0035] In a specific embodiment, one end of the fifth resistor R5 is connected to the emitter of the fifth transistor K5, the other end of the fifth resistor R5 is connected to the other end of the eighth resistor R8, one end of the sixth resistor R6 is connected to the emitter of the sixth transistor K6, the other end of the sixth resistor R6 is connected to the other end of the seventh resistor R7, one end of the seventh resistor R7 is connected to the emitter of the eleventh transistor K11, and one end of the eighth resistor R8 is connected to the emitter of the twelfth transistor K12.

[0036] In a specific embodiment, it also includes a first inductor L1, one end of the first inductor L1 is connected to the other end of the sixth resistor R6 and the other end of the seventh resistor R7, and the other end of the first inductor L1 is connected to the other end of the fifth resistor R5 and the other end of the eighth resistor R8 and grounded.

[0037] In a specific embodiment, the RF input stage of the first triode mixer and the second triode mixer includes a fifth triode K5, a sixth triode K6, a fifth resistor R5, a sixth resistor R6, a first inductor L1, an eleventh triode K11, a twelfth triode K12, a seventh resistor R7 and an eighth resistor R8, which are used to amplify the input signal, and the first intermediate frequency signal pair output by the first intermediate frequency port DT is input to the RF input stage.

[0038] In a specific embodiment, the second local oscillator signal pair includes an in-phase local oscillator signal pair and an orthogonal local oscillator signal pair, the in-phase local oscillator signal pair AL_I- and AL_I+ are input from the connection point between the base of the first transistor K1 and the base of the fourth transistor K4, and the connection point between the base of the second transistor K2 and the base of the third transistor K3, and the orthogonal local oscillator signal pair AL_Q- and AL_Q+ are input from the base of the seventh transistor K7 and the base of the tenth transistor K The first intermediate frequency signal pair DT is input from a connection point between the base of the fifth transistor K5 and the base of the twelfth transistor K12, that is, a first radio frequency input terminal AR+ of the transistor mixer, and a connection point between the base of the sixth transistor K6 and the base of the eleventh transistor K11, that is, a second radio frequency input terminal AR- of the transistor mixer.

[0039] In a specific embodiment, the second intermediate frequency signal pair includes an in-phase intermediate frequency signal pair and an orthogonal intermediate frequency signal pair, the in-phase intermediate frequency signal pair AT_I- and AT_I+ are output from the connection point between the collector of the first transistor K1 and the other end of the first resistor R1, and the connection point between the collector of the fourth transistor K4 and the other end of the second resistor R2, and the orthogonal intermediate frequency signal pair AT_Q- and AT_Q+ are output from the connection point between the collector of the seventh transistor K7 and the other end of the third resistor R3, and the connection point between the collector of the tenth transistor K10 and the other end of the fourth resistor R4.

[0040] The present application provides a mixer circuit, wherein an input signal is received by an antenna and input to a first radio frequency port DR of a diode mixer, and a conversion between balanced and unbalanced signals is realized through a first balun, and the radio frequency signal is transmitted and matched, etc., so as to better match and couple with the remaining circuit parts of the diode mixer, thereby improving the mixing efficiency and reducing interference, and the input radio frequency signal is modulated with the local oscillation signal of the diode mixer at the first local oscillator port, and impedance matching and common mode interference suppression are also performed by a second balun, and the unbalanced local oscillator signal is converted into a balanced signal, and preliminary mixing is performed by the diode mixer, and the first local oscillator is used to generate a balanced signal. The first intermediate frequency signal pair is output from the frequency port DT, and the first intermediate frequency signal pair is input into the triode mixer. The in-phase local oscillator signal pair AL_I- and AL_I+ and the orthogonal local oscillator signal pair AL_Q- and AL_Q+ of the triode mixer are used to modulate the first intermediate frequency signal pair input into the triode mixer. The secondary mixing outputs the in-phase intermediate frequency signal pair AT_I- and AT_I+ and the orthogonal intermediate frequency signal pair AT_Q- and AT_Q+. On the one hand, the advantages of the diode mixer are utilized to improve the linearity and noise performance, and can provide a relatively high linearity and low noise input signal for the subsequent triode mixer, thereby improving the overall mixer circuit. The linearity and noise performance of the circuit are suitable for processing application scenarios with high requirements on signal quality. At the same time, the diode mixer can work effectively in the RF and microwave bands. For high-frequency input signals, they are first processed by the diode mixer to convert the high-frequency signals into relatively low-frequency signals, which is convenient for subsequent triode mixers to further process and expand the operating frequency range of the entire mixing system. On the other hand, with the help of the characteristics of the triode mixer, a signal amplification function is provided. Although the linearity and noise performance of the signal after preliminary processing by the diode mixer are good, the signal strength is weak. When it is input to the triode mixer, Finally, the triode mixer can amplify the signal and improve the signal strength to meet the requirements of the subsequent circuit for signal amplitude, reduce the need for additional amplifiers, simplify the circuit structure, and combine the ability of the diode mixer to process small signals with the ability of the triode mixer to process large signals, thereby improving the dynamic range of the entire mixing system, and can handle various input conditions ranging from weak signals to larger signal amplitude changes, and can maintain good performance under different signal strengths, thereby enhancing the adaptability of the system. The inventor has fully simulated a mixer circuit of the present application, and the experimental results have verified that it can achieve the desired effect.

[0041] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A mixer circuit, characterized in that: include: A diode mixer, specifically comprising: a first balun, a second balun, and a first diode, a second diode, a third diode, and a fourth diode connected end to end in sequence, wherein the first balun is connected to a first end of the first diode and a second end of the fourth diode, the first balun is connected to a second end of the second diode and a first end of the third diode, the first balun is connected to a first radio frequency port and a first intermediate frequency port provided on the diode mixer, the second balun is connected to a second end of the first diode and a first end of the second diode, the second balun is connected to a second end of the third diode and a first end of the fourth diode, and the second balun is connected to a first local oscillator port provided on the diode mixer; The triode mixer specifically comprises: a first triode mixer and a second triode mixer, wherein the first triode mixer is electrically connected to the second triode mixer, and the first triode mixer and the second triode mixer both comprise: A radio frequency input stage, used for amplifying an input signal, wherein the first intermediate frequency signal pair output by the first intermediate frequency port is input to the radio frequency input stage; A local oscillator frequency conversion stage, using a second local oscillator signal pair to process the first intermediate frequency signal pair input to the triode mixer into a second intermediate frequency signal pair; An output load stage, used for converting the second intermediate frequency signal pair into a voltage signal and outputting the voltage signal; The first triode mixer specifically includes: a first triode, a second triode, a third triode, a fourth triode, a fifth triode and a sixth triode, the emitters of the first triode and the second triode are connected and connected to the collector of the fifth triode, the collector of the first triode is connected to the collector of the third triode and connected to the output load stage of the first triode mixer, the collector of the second triode is connected to the collector of the fourth triode and connected to the output load stage of the first triode mixer, the emitters of the third triode and the fourth triode are connected and connected to the collector of the sixth triode, the bases of the fifth triode and the sixth triode are both connected to the first intermediate frequency port, and the fifth triode and the sixth triode are both electrically connected to the second triode mixer; The second triode mixer specifically includes: a seventh triode, an eighth triode, a ninth triode, a tenth triode, an eleventh triode and a twelfth triode, the emitters of the seventh triode and the eighth triode are connected and connected to the collector of the eleventh triode, the collector of the seventh triode is connected to the collector of the ninth triode and connected to the output load stage of the second triode mixer, the collector of the eighth triode is connected to the collector of the tenth triode and connected to the output load stage of the second triode mixer, the emitters of the ninth triode and the tenth triode are connected and connected to the collector of the twelfth triode, the bases of the eleventh triode and the twelfth triode are both connected to the first intermediate frequency port, and the eleventh triode and the twelfth triode are both electrically connected to the first triode mixer.

2. A mixer circuit according to claim 1, characterized in that: The first triode mixer also includes a fifth resistor and a sixth resistor, and the second triode mixer also includes a seventh resistor and an eighth resistor, one end of the fifth resistor is connected to the emitter of the fifth triode, the other end of the fifth resistor is connected to the other end of the eighth resistor, one end of the sixth resistor is connected to the emitter of the sixth triode, the other end of the sixth resistor is connected to the other end of the seventh resistor, one end of the seventh resistor is connected to the emitter of the eleventh triode, and one end of the eighth resistor is connected to the emitter of the twelfth triode.

3. A mixer circuit according to claim 2, characterized in that: It also includes a first inductor, one end of which is connected to the other end of the sixth resistor and the other end of the seventh resistor, and the other end of the first inductor is connected to the other end of the fifth resistor and the other end of the eighth resistor.

4. The mixer circuit according to claim 1, characterized in that: The first transistor mixer also includes a first resistor and a second resistor, one end of the first resistor is connected to one end of the second resistor, the other end of the first resistor is connected to the collector of the first transistor, and the other end of the second resistor is connected to the collector of the fourth transistor.

5. A mixer circuit according to claim 4, characterized in that: The second transistor mixer also includes a third resistor and a fourth resistor, one end of the third resistor is connected to one end of the fourth resistor, the other end of the third resistor is connected to the collector of the seventh transistor, and the other end of the fourth resistor is connected to the collector of the tenth transistor.

6. The mixer circuit according to claim 1, characterized in that: The second local oscillator signal pair includes an in-phase local oscillator signal pair and an orthogonal local oscillator signal pair. The in-phase local oscillator signal pair is input from the connection point between the base of the first transistor and the base of the fourth transistor, and the connection point between the base of the second transistor and the base of the third transistor. The orthogonal local oscillator signal pair is input from the connection point between the base of the seventh transistor and the base of the tenth transistor, and the connection point between the base of the eighth transistor and the base of the ninth transistor. The first intermediate frequency signal pair is input from the connection point between the base of the fifth transistor and the base of the twelfth transistor, and the connection point between the base of the sixth transistor and the base of the eleventh transistor.

7. The mixer circuit according to claim 5, characterized in that: The second intermediate frequency signal pair includes an in-phase intermediate frequency signal pair and an orthogonal intermediate frequency signal pair. The in-phase intermediate frequency signal pair is output from the connection point between the collector of the first transistor and the other end of the first resistor, and the connection point between the collector of the fourth transistor and the other end of the second resistor. The orthogonal intermediate frequency signal pair is output from the connection point between the collector of the seventh transistor and the other end of the third resistor, and the connection point between the collector of the tenth transistor and the other end of the fourth resistor.

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