Terahertz monolithic integrated harmonic mixer

Abstract

The invention is suitable for the technical field of terahertz frequency mixing, and provides a terahertz monolithic integrated harmonic mixer. The mixer comprises a substrate and devices. The radio frequency port, the local oscillator port and the first matching transition structure are respectively connected with each coupling end of the coupler; the output end of the first matching transition structure is connected with the input end of the second matching transition structure and the first end of the anti-parallel diode pair. The second end of the anti-parallel diode pair is provided with a third grounding through hole. The output end of the second matching transition structure is connected with the input end of the low-pass filter; the output end of the low-pass filter is connected with the intermediate frequency port; the radio frequency port, the local oscillator port and the intermediate frequency port are GSG interfaces with grounding through holes; and a layer of metal is integrally arranged on the back surface of the substrate to connect the grounding through holes to form a coplanar waveguide. According to the mixer, harmonic mixing is realized through a simple process, the complexity is low, and meanwhile, the problems that the mixer cannot be integrated and the working frequency is low can be solved.

Description

Technical Field

[0001] This application belongs to the technical field of terahertz mixing technology, and particularly relates to a terahertz monolithic integrated harmonic mixer. Background Art

[0002] With the continuous progress of technology, especially the rapid development of microelectronics technology, in recent years, electronic devices have been continuously developing towards integration, miniaturization, and high frequency. Terahertz waves are electromagnetic spectra located between microwaves and infrared rays. With the continuous development of terahertz integrated circuits, terahertz technology has been widely used in fields such as communication, imaging detection, earth science, and astronomical planet exploration, demonstrating potential great value.

[0003] Currently, there are two types of structures for terahertz mixers. One type is a mixer with a waveguide as the transmission structure, which is characterized by the ability to achieve high-frequency mixing but cannot be integrated with other components of the system. The other type is an on-chip mixer with a microstrip line as the transmission structure, which is characterized by the ability to be integrated with the system, but the diode fabrication process limits the operating frequency of the mixer.

[0004] Therefore, it is necessary to solve the problem that the above mixers cannot balance integration and operating frequency. Summary of the Invention

[0005] To overcome the problems existing in the related art, an embodiment of this application provides a terahertz monolithic integrated harmonic mixer to solve the problem that the mixer in the prior art cannot balance integration and operating frequency.

[0006] This application is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of this application provides a terahertz monolithic integrated harmonic mixer, including a substrate and a radio frequency port, a local oscillator port, a coupler, a first matching transition structure, a second matching transition structure, a low-pass filter, a reverse parallel diode pair, and an intermediate frequency port disposed on the assembly surface of the substrate;

[0008] The radio frequency port is connected to the first coupling end of the coupler; the radio frequency port is a first GSG (ground-signal-ground) interface containing a first ground via;

[0009] The local oscillator port is connected to the second coupling end of the coupler; the local oscillator port is a second GSG interface containing a second ground via;

[0010] The third coupling end of the coupler is connected to the input end of the first matching transition structure; the output end of the first matching transition structure is respectively connected to the input end of the second matching transition structure and the first end of the reverse parallel diode pair; a third ground via is provided at the second end of the reverse parallel diode pair;

[0011] The output end of the second matching transition structure is connected to the input end of the low-pass filter;

[0012] The output end of the low-pass filter is connected to the intermediate-frequency port; the intermediate-frequency port is a third GSG interface including a fourth grounding via hole;

[0013] A layer of metal is integrally provided on the back surface of the substrate; the metal is used to connect the respective grounding via holes to form a coplanar waveguide.

[0014] In one embodiment, the radio-frequency port includes a first radio-frequency input port grounding pad, a radio-frequency input port signal pad, and a second radio-frequency input port grounding pad; the first radio-frequency input port grounding pad, the radio-frequency input port signal pad, and the second radio-frequency input port grounding pad form a first GSG interface; the radio-frequency input port signal pad is connected to the first coupling end of the coupler; the first radio-frequency input port grounding pad and the second radio-frequency input port grounding pad are grounded through a first grounding via hole.

[0015] In one embodiment, the local oscillator port includes a first local oscillator input port grounding pad, a local oscillator input port signal pad, and a second local oscillator input port grounding pad; the first local oscillator input port grounding pad, the local oscillator input port signal pad, and the second local oscillator input port grounding pad form a second GSG interface; the local oscillator input port signal pad is connected to the second coupling end of the coupler; the first local oscillator input port grounding pad and the second local oscillator input port grounding pad are grounded through a second grounding via hole.

[0016] In one embodiment, the intermediate-frequency port includes a first intermediate-frequency output port grounding pad, an intermediate-frequency output port signal pad, and a second intermediate-frequency output port grounding pad; the first intermediate-frequency output port grounding pad, the intermediate-frequency output port signal pad, and the second intermediate-frequency output port grounding pad form a third GSG interface; the intermediate-frequency output port signal pad is connected to the output end of the low-pass filter; the first intermediate-frequency output port grounding pad and the second intermediate-frequency output port grounding pad are grounded through a fourth grounding via hole.

[0017] In one embodiment, the antiparallel diode pair includes two quasi-vertical-structure gallium arsenide Schottky diodes.

[0018] In one embodiment, the first matching transition structure and the second matching transition structure are microstrip lines with different impedance values and different electrical lengths.

[0019] In one embodiment, the low-pass filter is a fan-shaped filter structure.

[0020] In one embodiment, the antiparallel diode pair includes a first diode and a second diode;

[0021] The positive electrode of the first diode is connected to the negative electrode of the second diode, and the negative electrode of the first diode is connected to the positive electrode of the second diode; the positive electrode of the first diode serves as the first end of the anti-parallel diode pair, and the negative electrode of the first diode serves as the second end of the anti-parallel diode pair.

[0022] In one embodiment, the RF port is connected to the first coupling end of the coupler through a microstrip line; the local oscillator port is connected to the second coupling end of the coupler through a microstrip line; the third coupling end of the coupler is connected to the input end of the first matching transition structure through a microstrip line.

[0023] In one embodiment, the coupler is a three-line coupler.

[0024] It can be understood that the beneficial effects of the second aspect above can be referred to the relevant descriptions in the first aspect above, and will not be elaborated here.

[0025] The beneficial effects of the embodiments of the present application compared with the prior art are as follows:

[0026] In the embodiments of the present application, the GSG interface is adopted to integrate key components such as the RF port, the local oscillator port, and the intermediate frequency port on the same substrate, realizing the integration of the waveguide structure mixer and other components of the system, reducing the complexity of external connections, improving the compactness and reliability of the device, while reducing signal transmission loss, which helps to achieve high-frequency operation. A layer of metal is integrally provided on the back of the substrate for connecting each ground, effectively reducing the influence of parasitic capacitance and inductance, improving the transmission efficiency of high-frequency signals, and thus supporting a higher operating frequency.

[0027] The RF port and the intermediate frequency port adopt a coplanar waveguide structure with a GSG interface, which is suitable for high-frequency signal transmission and can effectively support the operation in the terahertz frequency band. The anti-parallel diode pair is the core component of the mixer, which can achieve efficient frequency conversion, and by optimizing the parasitic parameters of the diode, the operating frequency can be further improved. At the same time, the first matching transition structure and the second matching transition structure are used to optimize the impedance matching of signal transmission. Good impedance matching can reduce signal reflection and improve transmission efficiency, thus supporting a higher operating frequency. The low-pass filter is used to filter out high-frequency interference signals to ensure the purity of the intermediate frequency output signal, which helps to improve the performance of the mixer.

[0028] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 is the structural topology diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of the present application;

[0031] Figure 2 is the circuit schematic diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of the present application;

[0032] Figure 3 is the structural model diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of the present application. Detailed implementation manners

[0033] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0034] It should be understood that when used in the specification and the appended claims of the present application, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0035] It should also be understood that the term "and / or" used in the specification and the appended claims of the present application refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0036] In addition, in the description of the specification and the appended claims of the present application, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0037] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that specific features, structures, or characteristics described in connection with that embodiment are included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in some other embodiments", "in still some other embodiments", etc. that appear at different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0038] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0039] Figure 1 is a schematic structural diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of this application, Figure 2 is a schematic circuit diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of this application, Figure 3 is a structural model diagram of a terahertz monolithic integrated harmonic mixer provided by an embodiment of this application. Referring to Figures 1 to 3 , the detailed description of this terahertz monolithic integrated harmonic mixer is as follows:

[0040] An embodiment of this application provides a terahertz monolithic integrated harmonic mixer, which includes a substrate 100 and a radio frequency port 200, a local oscillator port 300, a coupler 400, a first matching transition structure 500, a second matching transition structure 600, a low-pass filter 700, an antiparallel diode pair 800, and an intermediate frequency port 900 disposed on the assembly surface of the substrate 100.

[0041] The radio frequency port 200 is connected to the first coupling end of the coupler 400; the radio frequency port 200 is a first GSG interface containing a first ground via.

[0042] The local oscillator port 300 is connected to the second coupling end of the coupler 400; the local oscillator port 300 is a second GSG interface containing a second ground via.

[0043] The third coupling end of the coupler 400 is connected to the input end of the first matching transition structure 500; the output end of the first matching transition structure 500 is respectively connected to the input end of the second matching transition structure 600 and the first end of the antiparallel diode pair 800; a third ground via is provided at the second end of the antiparallel diode pair 800.

[0044] The output end of the second matching transition structure 600 is connected to the input end of the low-pass filter 700.

[0045] The output terminal of the low-pass filter 700 is connected to the intermediate-frequency port 900; the intermediate-frequency port 900 is a third GSG interface containing a fourth ground via hole.

[0046] A layer of metal is integrally provided on the back surface of the substrate 100; this metal is used to connect each ground via hole to form a coplanar waveguide.

[0047] Exemplarily, the assembly surface of the substrate 100 is the front side of the device, which is used to integrate and install all key circuit components and structures. The back surface of the substrate 100 is the other side of the device, which is mainly used to provide grounding and electromagnetic shielding functions. Specifically, the back surface of the substrate 100 is integrally covered with a layer of metal (usually a highly conductive metal such as copper or gold). The main function of this layer of metal is to connect each ground via hole on the assembly surface to form a low-impedance ground plane. The ground layer can effectively shield external electromagnetic interference and at the same time reduce crosstalk between internal signals. This design is particularly important for high-frequency signal transmission because it can reduce the influence of parasitic capacitance and inductance, improve signal integrity and transmission efficiency. In high-frequency and high-power applications, the metal layer on the back can also play a certain role in heat dissipation, helping to maintain the stable operation of the device.

[0048] Exemplarily, the coupler 400 is a three-line coupler, which uses a coupler structure to isolate the local oscillator and the radio frequency, and does not require a separate radio frequency filtering structure and local oscillator filtering structure.

[0049] In this embodiment, the GSG interface is adopted to integrate key components such as the radio frequency port 200, the local oscillator port 300, and the intermediate-frequency port 900 on the same substrate 100, realizing the integration of the waveguide structure mixer and other components of the system, reducing the complexity of external connections, improving the compactness and reliability of the device, and at the same time reducing signal transmission loss, which helps to achieve high-frequency operation. A layer of metal is integrally provided on the back surface of the substrate 100 to connect each ground, effectively reducing the influence of parasitic capacitance and inductance, improving the transmission efficiency of high-frequency signals, and thus supporting higher operating frequencies.

[0050] The radio frequency port 200 and the intermediate-frequency port 900 adopt a coplanar waveguide structure containing a GSG interface, which is suitable for high-frequency signal transmission and can effectively support operation in the terahertz frequency band. The reverse parallel diode pair 800 is the core component of the mixer, which can achieve efficient frequency conversion, and by optimizing the parasitic parameters of the diode, the operating frequency can be further increased. At the same time, the first matching transition structure 500 and the second matching transition structure 600 are used to optimize the impedance matching of signal transmission. Good impedance matching can reduce signal reflection, improve transmission efficiency, and thus support higher operating frequencies. The low-pass filter 700 is used to filter out high-frequency interference signals to ensure the purity of the intermediate-frequency output signal, which helps to improve the performance of the mixer.

[0051] In one embodiment, the radio frequency port 200 includes a first radio frequency input port ground contact 201, a radio frequency input port signal contact 202, and a second radio frequency input port ground contact 203; the first radio frequency input port ground contact 201, the radio frequency input port signal contact 202, and the second radio frequency input port ground contact 203 form a coplanar waveguide; the radio frequency input port signal contact 202 is connected to the first coupling end of the coupler 400; the first radio frequency input port ground contact 201 and the second radio frequency input port ground contact 203 are grounded through a first ground via.

[0052] In this embodiment, by forming a coplanar waveguide with the first radio frequency input port ground contact 201, the radio frequency input port signal contact 202, and the second radio frequency input port ground contact 203, this structure helps to optimize the transmission characteristics of radio frequency signals. The coplanar waveguide structure can reduce the loss and interference during signal transmission, and improve the stability and efficiency of radio frequency signal transmission. The radio frequency input port signal contact 202 is connected to the first coupling end of the coupler 400, enabling the radio frequency signal to be effectively processed by the coupler 400, thereby realizing specific radio frequency functions such as signal distribution and synthesis. Moreover, the first radio frequency input port ground contact 201 and the second radio frequency input port ground contact 203 are grounded through a first ground via. A good grounding design can further enhance the stability of the system, reduce the impact of electromagnetic interference on radio frequency signals, ensure the normal operation of the radio frequency circuit, and improve the performance and reliability of the entire radio frequency system.

[0053] In one embodiment, the local oscillator port 300 includes a first local oscillator input port ground contact 301, a local oscillator input port signal contact 302, and a second local oscillator input port ground contact 303; the first local oscillator input port ground contact 301, the local oscillator input port signal contact 302, and the second local oscillator input port ground contact 303 form a coplanar waveguide; the local oscillator input port signal contact 302 is connected to the second coupling end of the coupler 400; the first local oscillator input port ground contact 301 and the second local oscillator input port ground contact 303 are grounded through a second ground via.

[0054] In this embodiment, by forming a coplanar waveguide with the first local oscillator input port ground contact 301, the local oscillator input port signal contact 302, and the second local oscillator input port ground contact 303, it can effectively improve the stability and efficiency of signal transmission. The coplanar waveguide structure helps to reduce the interference and loss during signal transmission, ensuring the high-quality transmission of the local oscillator signal. The local oscillator input port signal contact 302 is connected to the second coupling end of the coupler 400. This connection method enables the local oscillator signal to be accurately transmitted into the coupler 400, realizing effective signal coupling, and providing a stable local oscillator signal source for subsequent signal processing.

[0055] The ground pressure point 301 of the first local oscillator input port and the ground pressure point 303 of the second local oscillator input port are grounded through the second grounding via hole. A good grounding design can effectively suppress electromagnetic interference and improve the anti-interference ability of the circuit. Grounding can provide a stable reference potential for the signal, avoid signal fluctuations caused by external interference, ensure the normal operation of the entire circuit system, and improve the reliability and stability of the device.

[0056] In one embodiment, the intermediate frequency port 900 includes a ground pressure point 901 of the first intermediate frequency output port, a signal pressure point 902 of the intermediate frequency output port, and a ground pressure point 903 of the second intermediate frequency output port; the ground pressure point 901 of the first intermediate frequency output port, the signal pressure point 902 of the intermediate frequency output port, and the ground pressure point 903 of the second intermediate frequency output port form a coplanar waveguide; the signal pressure point 902 of the intermediate frequency output port is connected to the output end of the low-pass filter 700; the ground pressure point 901 of the first intermediate frequency output port and the ground pressure point 903 of the second intermediate frequency output port are grounded through the fourth grounding via hole.

[0057] In this embodiment, by forming a coplanar waveguide with the ground pressure point 901 of the first intermediate frequency output port, the signal pressure point 902 of the intermediate frequency output port, and the ground pressure point 903 of the second intermediate frequency output port, the intermediate frequency signal can be effectively transmitted, and the loss and interference during signal transmission can be reduced. The coplanar waveguide structure has good electromagnetic characteristics, which is beneficial to improving the signal transmission quality. The signal pressure point 902 of the intermediate frequency output port is connected to the output end of the low-pass filter 700, and the signal can be filtered to remove unnecessary high-frequency components, making the output intermediate frequency signal purer. The ground pressure point 901 of the first intermediate frequency output port and the ground pressure point 903 of the second intermediate frequency output port are grounded through the fourth grounding via hole, which can provide a good grounding effect, further enhance the stability of the circuit, reduce the influence of electromagnetic interference on signal transmission, and thus improve the performance and reliability of the entire system.

[0058] In one embodiment, the antiparallel diode pair 800 includes two gallium arsenide Schottky diodes with a quasi-vertical structure. The quasi-vertical structure is an N+ / N- vertical material structure, and the gallium arsenide Schottky diode and the circuit are formed into a terahertz mixer circuit through a single process.

[0059] Exemplarily, the antiparallel diode pair 800 includes a first diode 801 and a second diode 802. Both the first diode and the second diode are gallium arsenide Schottky diodes with a quasi-vertical structure.

[0060] The positive electrode of the first diode 801 is connected to the negative electrode of the second diode 802, and the negative electrode of the first diode 801 is connected to the positive electrode of the second diode 802; the positive electrode of the first diode 801 serves as the first end of the antiparallel diode pair 800, and the negative electrode of the first diode 801 serves as the second end of the antiparallel diode pair 800.

[0061] Exemplarily, the first ends of the anti-parallel diode pair 800 are respectively connected to the output end of the first matching transition structure 500 and the input end of the second matching transition structure 600; the second ends of the anti-parallel diode pair 800 are connected to the third grounding via hole, that is, the second ends of the anti-parallel diode pair 800 form a coplanar waveguide with the metal on the back of the substrate 100 through the third grounding via hole to form a ground, providing a stable DC bias condition for the diode. This grounding method ensures that the diode has a clear reference potential during operation, thereby ensuring the stable operation of its non-linear characteristics. At the same time, it can effectively suppress parasitic signals and noise in high-frequency signals, optimize the signal transmission path, and reduce signal reflection and loss.

[0062] The anti-parallel diode pair 800 composed of the quasi-vertical structure gallium arsenide Schottky diodes in this embodiment, due to the adoption of the N+ / N- vertical material structure, enables the integration of gallium arsenide Schottky diodes and circuits through a single process when manufacturing a terahertz mixer circuit, greatly simplifying the manufacturing process and improving production efficiency. Moreover, the diode pair with this structure can provide better performance in the terahertz mixer circuit. For example, during the signal mixing process, it can reduce signal loss and distortion. In terms of circuit connection, the first diode 801 and the second diode 802 form the anti-parallel diode pair 800 according to a specific connection method. This connection method makes the current transmission in the circuit more stable, and the settings of the first end and the second end also facilitate the access and overall layout of the circuit, which is beneficial to the miniaturization and integrated design of the entire terahertz mixer circuit.

[0063] The harmonic mixer formed by combining the monolithic integration with GSG interfaces and the material system with a vertical structure in this embodiment can solve the problem that traditional waveguide structure mixers cannot be integrated with other components of the system, and can also realize high cut-off frequency diodes, thereby increasing the operating frequency of the mixer.

[0064] In one embodiment, the first matching transition structure 500 and the second matching transition structure 600 are microstrip lines with different impedance values and different electrical lengths.

[0065] The microstrip lines with different impedance values and different electrical lengths are set in this embodiment, enabling more flexible matching and transition control of signal transmission in the circuit system. Different impedance values can be adjusted according to the input and output impedance requirements of the specific circuit to achieve the best power transmission efficiency, reduce signal reflection, and improve signal integrity. Different electrical lengths help to adjust the phase of the signal at different frequencies, which is very beneficial for the design of multi-frequency or broadband circuits.

[0066] In one embodiment, the low-pass filter 700 is a fan-shaped filter structure.

[0067] Exemplarily, a sector filter structure is adopted, which has the advantages of compact structure and low loss.

[0068] In one embodiment, the radio frequency port 200 is connected to the first coupling end of the coupler 400 through a microstrip line; the local oscillator port 300 is connected to the second coupling end of the coupler 400 through a microstrip line; the third coupling end of the coupler 400 is connected to the input end of the first matching transition structure 500 through a microstrip line.

[0069] Exemplarily, in order to better describe the parts using microstrip lines clearly, the terahertz monolithic integrated harmonic mixer includes the first microstrip line 111 to the fifth microstrip line 115. The signal contact point 202 of the radio frequency input port is connected to the first coupling end of the coupler 400 through the first microstrip line 111; the signal contact point 302 of the local oscillator input port is connected to the second coupling end of the coupler 400 through the second microstrip line 112; the third coupling end of the coupler 400 is connected to the input end of the first matching transition structure 500 through the third microstrip line 113; the second matching transition structure 600 is connected to the low-pass filter 700 through the fourth microstrip line 114; the signal contact point 902 of the intermediate frequency output port is connected to the low-pass filter 700 through the fifth microstrip line 115.

[0070] In this embodiment, the radio frequency port 200 is connected to the first coupling end of the coupler 400, the local oscillator port 300 is connected to the second coupling end of the coupler 400, and the third coupling end of the coupler 400 is connected to the input end of the first matching transition structure 500 through microstrip lines. This connection method has many advantages. First of all, microstrip lines have the characteristics of small volume and light weight, which can effectively reduce the size of the entire circuit structure and make it more suitable for application scenarios with high space requirements, such as miniaturized communication devices, etc. Secondly, the transmission performance of microstrip lines is stable, and it can maintain low loss in a relatively wide frequency range, thus ensuring the quality of radio frequency signals and local oscillator signals during transmission and reducing the possibility of signal attenuation and distortion. Moreover, this connection method is more flexible in circuit layout and can be reasonably wired according to specific circuit design requirements, which is convenient for optimizing the overall performance of the circuit, such as achieving better electromagnetic compatibility, etc.

[0071] It can be seen that the terahertz monolithic integrated harmonic mixer proposed by the present invention adopts a GSG interface, integrates key components such as the radio frequency port 200, the local oscillator port 300, and the intermediate frequency port 900 on the same substrate 100, realizes the integration of the waveguide structure mixer and other components of the system, reduces the complexity of external connections, improves the compactness and reliability of the device, and at the same time reduces signal transmission loss, which helps to achieve high-frequency operation. A layer of metal is integrally provided on the back of the substrate 100 for connecting each ground, effectively reducing the influence of parasitic capacitance and inductance, improving the transmission efficiency of high-frequency signals, and thus supporting higher operating frequencies.

[0072] Meanwhile, a material system with a vertical structure can be used to implement a high cut-off frequency diode, thereby improving the operating frequency of the mixer.

[0073] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0074] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A terahertz monolithic integrated harmonic mixer, characterized in that: It includes a substrate and a radio frequency port, a local oscillator port, a coupler, a first matching transition structure, a second matching transition structure, a low-pass filter, an anti-parallel diode pair and an intermediate frequency port arranged on the assembly surface of the substrate; The RF port is connected to the first coupling end of the coupler; the RF port is a first GSG interface having a first grounding through hole The local oscillator port is connected to the second coupling end of the coupler; the local oscillator port is a second GSG interface having a second ground through hole; The third coupling end of the coupler is connected to the input end of the first matching transition structure; the output end of the first matching transition structure is respectively connected to the input end of the second matching transition structure and the first end of the anti-parallel diode pair; and a third grounding through hole is provided at the second end of the anti-parallel diode pair; The output end of the second matching transition structure is connected to the input end of the low-pass filter; The output end of the low-pass filter is connected to the intermediate frequency port; the intermediate frequency port is a third GSG interface including a fourth ground through hole; A layer of metal is disposed on the entire back side of the substrate; the metal is used to connect various grounding through holes to form a coplanar waveguide.

2. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The RF port includes a first RF input port grounding voltage point, a RF input port signal voltage point, and a second RF input port grounding voltage point; the first RF input port grounding voltage point, the RF input port signal voltage point, and the second RF input port grounding voltage point form a first GSG interface; the RF input port signal voltage point is connected to the first coupling end of the coupler; The first RF input port grounding voltage point and the second RF input port grounding voltage point are grounded through a first grounding through hole.

3. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The local oscillator port includes a first local oscillator input port grounding pressure point, a local oscillator input port signal pressure point, and a second local oscillator input port grounding pressure point; the first local oscillator input port grounding pressure point, the local oscillator input port signal pressure point, and the second local oscillator input port grounding pressure point form a second GSG interface; The signal pressure point of the local oscillator input port is connected to the second coupling end of the coupler; The first local oscillator input port grounding voltage point and the second local oscillator input port grounding voltage point are grounded through a second grounding through hole.

4. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The intermediate frequency port includes a first intermediate frequency output port grounding pressure point, an intermediate frequency output port signal pressure point, and a second intermediate frequency output port grounding pressure point; the first intermediate frequency output port grounding pressure point, the intermediate frequency output port signal pressure point, and the second intermediate frequency output port grounding pressure point form a third GSG interface; The intermediate frequency output port signal pressure point is connected to the output end of the low-pass filter; the first intermediate frequency output port ground pressure point and the second intermediate frequency output port ground pressure point are grounded through a fourth grounding through hole.

5. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The anti-parallel diode pair includes two GaAs Schottky diodes in a quasi-vertical structure.

6. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The first matching transition structure and the second matching transition structure are microstrip lines with different impedance values ​​and different electrical lengths.

7. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The low-pass filter is a fan-shaped filter structure.

8. The terahertz monolithic integrated harmonic mixer according to claim 1, characterized in that: The anti-parallel diode pair includes a first diode and a second diode; The anode of the first diode is connected to the cathode of the second diode, and the cathode of the first diode is connected to the anode of the second diode; the anode of the first diode serves as the first end of the reverse-parallel diode pair, and the cathode of the first diode serves as the second end of the reverse-parallel diode pair.

9. The terahertz monolithic integrated harmonic mixer according to any one of claims 1 to 8, characterized in that: The RF port is connected to the first coupling end of the coupler through a microstrip line; the local oscillator port is connected to the second coupling end of the coupler through a microstrip line; the third coupling end of the coupler is connected to the input end of the first matching transition structure through a microstrip line.

10. The terahertz monolithic integrated harmonic mixer according to any one of claims 1 to 8, characterized in that: The coupler is a three-wire coupler.

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