Terahertz frequency multiplier

Abstract

The terahertz frequency multiplier comprises an inner conductor leading-out direct connection structure, a transition structure of a micro-coaxial input waveguide, the input waveguide, a micro-coaxial input low-pass filter, a diode pair, a transition structure of a micro-coaxial output waveguide, two micro-coaxial matching circuits and an output waveguide, the first end of the inner conductor lead-out direct-connection structure is directly connected with an external direct-current bias circuit through a micro-coaxial inner conductor, the second end of the inner conductor lead-out direct-connection structure is coaxially connected with the transition structure of the micro-coaxial input waveguide, and the inner conductor lead-out direct-connection structure is used for introducing bias voltage of the external direct-current bias circuit to reduce distortion. According to the invention, the loss introduced by the substrate is reduced, the size of the whole circuit is reduced, and miniaturization is realized. Meanwhile, a traditional direct current filter circuit can be omitted, on one hand, the circuit complexity is reduced, on the other hand, complex conversion of a traditional frequency mixer is avoided, and the circuit loss is further reduced.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a terahertz frequency multiplier. Background Art

[0002] For the application field of terahertz frequency band, high-quality terahertz frequency source is the key to the application of terahertz system, and its performance largely determines the performance of the system. At present, terahertz solid-state frequency source is developing towards higher frequency, greater power, wider bandwidth, monolithic integration, ultra-low phase noise and other directions.

[0003] In the terahertz frequency band, due to the high operating frequency, the transmission loss of the transmission line cannot be ignored. Existing terahertz frequency multipliers often use suspended microstrip lines, microstrip lines, coplanar waveguides, etc. with shielded cavities as waveguide systems. Among them, the most obvious feature is that the reverse-parallel Schottky diode pairs are flip-chip packaged and bonded to the substrate with silver glue.

[0004] Terahertz frequency multipliers often use rectangular waveguide structures, and nonlinear devices are arranged on microstrip lines. Although the terahertz frequency microstrip line structure can transmit electromagnetic fields, the loss is relatively high. In order to achieve low loss, the substrate is often made of quartz glass, which means that the substrate cannot be too long and it is impossible to design torsional structures, otherwise the quartz will break. The existing microstrip line structure not only increases the connection loss inside the frequency multiplier, but also limits the design of the frequency multiplier circuit.

[0005] At the same time, if the losses in the frequency multiplier are high, these losses will be converted into thermal effects during operation. The accumulation of heat will affect the working state of the diode, reduce the performance of the diode, and thus deteriorate the frequency multiplication efficiency and output power of the frequency multiplier. Summary of the invention

[0006] The purpose of the present application is to provide a terahertz frequency doubler to solve the technical problem that the loss of the terahertz frequency doubler in the prior art is large, thereby affecting the frequency doubling efficiency. The preferred technical solution among the many technical solutions provided in the present application can produce many technical effects as described below.

[0007] To achieve the above objectives, this application provides the following technical solutions:

[0008] The present application provides a terahertz frequency multiplier, comprising: an inner conductor lead-out direct connection structure, a transition structure of a micro-coaxial input waveguide, an input waveguide for receiving an input signal, a micro-coaxial input low-pass filter for filtering the input signal, a diode pair for frequency-multiplying and amplifying the filtered input signal to generate an output signal, a transition structure of a micro-coaxial output waveguide, two micro-coaxial matching circuits and an output waveguide for transmitting the output signal; a first end of the inner conductor lead-out direct connection structure is directly connected to an external DC bias circuit through an inner conductor of the micro-coaxial, a second end of the inner conductor lead-out direct connection structure is coaxially connected to the transition structure of the micro-coaxial input waveguide, and the inner conductor lead-out direct connection structure is used to introduce the external The bias voltage of the DC bias circuit of the part is used to reduce distortion; the first end of the transition structure of the micro-coaxial input waveguide is coaxially connected to the second end of the inner conductor lead-out direct connection structure, the second end of the transition structure of the micro-coaxial input waveguide is connected to the input waveguide, and the third end of the transition structure of the micro-coaxial input waveguide is coaxially connected to the input low-pass filter of the micro-coaxial; the first end of the diode pair is coaxially connected to the input low-pass filter of the micro-coaxial through one of the micro-coaxial matching circuits, the second end of the diode pair is coaxially connected to the first end of the transition structure of the micro-coaxial output waveguide through another micro-coaxial matching circuit, wherein the second end of the transition structure of the micro-coaxial output waveguide is connected to the output waveguide.

[0009] In some embodiments, the transition structure of the micro-coaxial input waveguide includes an input probe, which is formed by extending into the interior of the input waveguide through an inner conductor of the transition structure of the micro-coaxial input waveguide, and is used for impedance matching between the transition structure of the micro-coaxial input waveguide and the input waveguide.

[0010] In some embodiments, the first end of the input waveguide is used to receive the input signal, and the second end of the input waveguide is connected to the input probe; the first end of the input probe is coaxially connected to the second end of the inner conductor lead-out direct connection structure, the second end of the input probe is connected to the second end of the input waveguide, and the third end of the input probe is coaxially connected to the first end of the micro-coaxial input low-pass filter.

[0011] In some embodiments, the diode pair is directly connected to the inner conductor of the micro-coaxial matching circuit at both ends of the diode pair.

[0012] In some embodiments, the inner conductor of the micro-coaxial input low-pass filter includes a plurality of rectangular branches.

[0013] In some embodiments, the terahertz frequency multiplier includes a micro-coaxial arched matching structure for heat dissipation of the diode pair; a first end of the micro-coaxial arched matching structure is coaxially connected to the diode pair, and the micro-coaxial arched matching structure is coaxially connected to a transition structure of an output waveguide of the micro-coaxial.

[0014] In some embodiments, the diode pair is Schottky diodes connected in parallel in phase.

[0015] In some embodiments, the transition structure of the micro-coaxial output waveguide includes an output probe, which is formed by extending toward the interior of the output waveguide through an inner conductor of the transition structure of the micro-coaxial output waveguide, and is used for impedance matching between the transition structure of the micro-coaxial output waveguide and the output waveguide.

[0016] In some embodiments, the first end of the output probe is coaxially connected to the diode pair through the arch matching structure of the micro-coaxial; the first end of the output waveguide is connected to the second end of the output probe, and the second end of the output waveguide is used to output the output signal.

[0017] In some embodiments, the external DC bias circuit directly leads out the inner conductor of the direct connection structure from the inner conductor through the SMA coaxial line to perform DC feeding on the terahertz frequency multiplier.

[0018] Implementing one of the above technical solutions of the present application has the following advantages or beneficial effects: In the present application, two micro-coaxial matching circuits of the terahertz frequency multiplier diode pair and the input low-pass filter of the micro-coaxial are designed through a micro-coaxial structure, so no substrate structure can be used in the circuit, thereby reducing the loss introduced by the substrate. At the same time, due to the use of the input low-pass filter of the micro-coaxial, the size of the entire circuit is also reduced, and miniaturization is achieved. In addition, since the inner conductor lead-out direct connection structure adopts a micro-coaxial structure, the DC bias circuit can be directly fed with DC from the inner conductor through the SMA coaxial line, thereby eliminating the traditional DC filter circuit, which reduces the complexity of the circuit on the one hand, and avoids the complex transformation of the traditional mixer quartz substrate-5880 soft substrate-coaxial line on the other hand, further reducing the circuit loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. It is obvious that the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0020] Figure 1is a structural block diagram of a terahertz frequency multiplier according to an embodiment of the present application;

[0021] Figure 2 is a schematic diagram of a rectangular micro-coaxial line according to an embodiment of the present application;

[0022] Figure 3 is a schematic structural diagram of a terahertz frequency multiplier according to an embodiment of the present application;

[0023] Figure 4 is a structural perspective view of a terahertz frequency multiplier according to an embodiment of the present application;

[0024] Figure 5 It is a schematic diagram of the structure of the inner conductor of the terahertz frequency multiplier according to an embodiment of the present application.

[0025] In the figure: 1. terahertz frequency multiplier; 11. inner conductor lead-out direct connection structure; 12. transition structure of micro-coaxial input waveguide; 13. input waveguide; 14. micro-coaxial input low-pass filter; 15. diode pair; 16. transition structure of micro-coaxial output waveguide; 17. output waveguide; 18. arch matching structure; 120. input probe; 160. output probe. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the various exemplary embodiments to be described below will refer to the corresponding drawings, which constitute a part of the exemplary embodiments, wherein various exemplary embodiments that may be used to implement the present application are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present disclosure. It should be understood that they are only examples of processes, methods, and devices that are consistent with some aspects disclosed in the present application as detailed in the attached claims, and other embodiments may also be used, or the embodiments listed herein may be modified in structure and function without departing from the scope and essence of the present application.

[0027] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", etc. indicate the orientation or positional relationship based on the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "multiple" means two or more. The terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0028] In order to illustrate the technical solution described in the present application, a specific embodiment is provided below, and only the parts related to the embodiment of the present application are shown.

[0029] The frequency multiplier is an active circuit that uses the nonlinear characteristics of a diode to achieve frequency multiplication, and is the core of a terahertz solid-state frequency source. Terahertz frequency multipliers often use a rectangular waveguide structure, and nonlinear devices are arranged on microstrip lines. Although the microstrip line structure in the terahertz band can transmit electromagnetic fields, the loss is relatively high, and in order to achieve low loss, quartz glass is often used as the substrate, which means that the substrate cannot be too long, and it is impossible to design a torsion structure, otherwise the quartz will break. Therefore, the connection loss inside the frequency multiplier is increased, and the design of the frequency multiplier circuit is also limited.

[0030] like Figure 1 As shown, the present application provides a terahertz frequency multiplier 1, which may include an inner conductor lead-out direct connection structure 11, a transition structure 12 of a micro-coaxial input waveguide, an input waveguide 13 for receiving an input signal, a micro-coaxial input low-pass filter 14 for filtering the input signal, a diode pair 15 for frequency-multiplying and amplifying the filtered input signal to generate an output signal, a transition structure 16 of a micro-coaxial output waveguide, two micro-coaxial matching circuits and an output waveguide 17 for transmitting the output signal.

[0031] In some embodiments, the input signal and the output signal may be a local oscillator signal or a radio frequency signal. That is, the terahertz frequency multiplier 1 of the embodiment of the present application may be used to perform frequency multiplication and amplification processing on the local oscillator signal or the radio frequency signal.

[0032] In some embodiments, the terahertz frequency multiplier 1 can use a rectangular micro-coaxial line for signal transmission. Figure 2 As shown, the rectangular micro coaxial line may include an inner conductor, a dielectric support and an outer shielding cavity. Specifically, the inner conductor may be a closed structure, the inner conductor may be arranged inside the outer shielding cavity, a dielectric support is arranged between the inner conductor and the outer shielding cavity, and the signal may be transmitted through the inner conductor.

[0033] In some embodiments, the transmission mode of the rectangular micro-coaxial line is the TEM mode. Therefore, the use of the rectangular micro-coaxial line for transmission has the advantages of low dispersion and low loss, and can enable the terahertz frequency multiplier 1 to operate at a wider operating frequency.

[0034] In summary, the traditional rectangular waveguide has high-pass characteristics. For a rectangular waveguide of fixed size, it can only transmit electromagnetic waves of a fixed frequency band and cannot transmit broadband. At the same time, because the inner conductor of the rectangular micro-coaxial line is closed and has high isolation, even if two rectangular micro-coaxial lines are very close to each other, their mutual interference is extremely small, so they can be wired very close to each other. By adjusting the size of the inner conductor, it is easy to change the impedance. In addition, the performance of the rectangular micro-coaxial line is not affected by bending and cross-coupling, which facilitates the construction of complex circuits and devices, thereby achieving a high degree of integration of the circuit system.

[0035] In some embodiments, the terahertz frequency multiplier 1 may be a 220 GHz frequency tripler. For example, when the input signal received by the terahertz frequency multiplier 1 is f0, the output signal delivered by the terahertz frequency multiplier 1 may be 3f0.

[0036] In some embodiments, the first end of the inner conductor lead-out direct connection structure 11 can be directly connected to an external DC bias circuit through the inner conductor of the micro-coaxial, and the second end of the inner conductor lead-out direct connection structure 11 can be coaxially connected to the transition structure 12 of the micro-coaxial input waveguide. The inner conductor lead-out direct connection structure 11 can be used to introduce the bias voltage of the external DC bias circuit to reduce distortion.

[0037] In some embodiments, the external DC bias circuit can be directly led out from the inner conductor through the SMA coaxial line to the inner conductor of the direct connection structure 11 to feed the terahertz frequency multiplier 1 with DC power. Since the DC bias can be directly loaded through the inner conductor, the volume can be reduced by 50% compared with the traditional frequency multiplier. The SMA (SubMiniatureversion A) coaxial line is a radio frequency coaxial cable connector.

[0038] In the conventional frequency multiplier structure based on microstrip lines, since the substrate is often made of quartz substrate or other materials, the inner conductor of the coaxial connector cannot be directly connected to it, and an additional 5880 soft substrate transition needs to be set, which increases the volume of the circuit, the connection loss and the difficulty of overall processing. The inner conductor lead-out direct connection structure 11 of the embodiment of the present application can be formed by directly extending the rectangular micro-coaxial line, so the embodiment of the present application has the advantages of simple structure, convenient connection, low loss, small volume, etc.

[0039] In some embodiments, the inner conductor of the inner conductor lead-out direct connection structure 11 can extend from one end to the other end of the inner conductor lead-out direct connection structure 11. In other words, the inner conductor of the inner conductor lead-out direct connection structure 11 can be directly connected to the inner conductor of the inner conductor lead-out direct connection structure 11 through both ends.

[0040] In some embodiments, Figures 3 to 5 As shown, the first end of the transition structure 12 of the micro-coaxial input waveguide can be coaxially connected to the second end of the inner conductor lead-out direct connection structure 11, the second end of the transition structure 12 of the micro-coaxial input waveguide can be connected to the input waveguide 13, and the third end of the transition structure 12 of the micro-coaxial input waveguide can be coaxially connected to the micro-coaxial input low-pass filter 14. The inner conductor of the transition structure 12 of the micro-coaxial input waveguide can be directly connected to the inner conductor of the inner conductor lead-out direct connection structure 11, and the inner conductor of the transition structure 12 of the micro-coaxial input waveguide can be directly connected to the inner conductor of the micro-coaxial input low-pass filter 14.

[0041] In some embodiments, the transition structure 12 of the micro-coaxial input waveguide may include an input probe 120, which may be formed by extending the inner conductor of the transition structure 12 of the micro-coaxial input waveguide to the inside of the input waveguide 13, and is used for impedance matching between the transition structure 12 of the micro-coaxial input waveguide and the input waveguide 13. Therefore, in the embodiment of the present application, when the transition structure 12 of the micro-coaxial input waveguide transitions to the input waveguide 13, it is only necessary to extend the inner conductor outward, so the structure is simple and the circuit size is small.

[0042] In some embodiments, the input probe 120 may be a T-shaped structure.

[0043] In some embodiments, the first end of the input waveguide 13 can be used to receive an input signal, and the second end of the input waveguide 13 can be connected to the input probe 120; the first end of the input probe 120 can be coaxially connected to the second end of the inner conductor lead-out direct connection structure 11, the second end of the input probe 120 can be connected to the second end of the input waveguide 13, and the third end of the input probe 120 can be coaxially connected to the first end of the micro-coaxial input low-pass filter 14.

[0044] In some embodiments, the inner conductor of the micro-coaxial input low-pass filter 14 may include a plurality of rectangular branches. Specifically, the inner conductor of the micro-coaxial input low-pass filter 14 may extend in a direction perpendicular to the extension direction of the inner conductor to form a plurality of rectangular branches. Thus, the impedance can be changed, thereby achieving the performance of the resonant cavity and satisfying the filtering effect.

[0045] Compared with a microstrip line filter, the structure of the micro-coaxial input low-pass filter 14 can reduce the lateral length of the circuit and the overall size can be reduced by 20%.

[0046] In some embodiments, the first end of the diode pair 15 can be coaxially connected to the micro-coaxial input low-pass filter 14 through a micro-coaxial matching circuit, and the second end of the diode pair 15 can be coaxially connected to the first end of the transition structure 16 of the micro-coaxial output waveguide through another micro-coaxial matching circuit, wherein the second end of the transition structure 16 of the micro-coaxial output waveguide is connected to the output waveguide 17. The inner conductor of one micro-coaxial matching circuit can be directly connected to the inner conductor of the micro-coaxial input low-pass filter 14, and the other micro-coaxial matching circuit can be directly connected to the inner conductor of the transition structure 16 of the micro-coaxial output waveguide.

[0047] In some embodiments, the diode pair 15 can be directly connected to the inner conductor of the micro-coaxial matching circuit at both ends of the diode pair 15. In this case, multiple coaxial to microstrip line transitions can be omitted, making the circuit structure of the terahertz frequency multiplier 1 more compact; the heat dissipation area of ​​the diode pair 15 can be increased, reducing the impact of heat accumulation on the performance of the terahertz frequency multiplier 1.

[0048] The traditional frequency multiplier diode integration method is mainly based on the flip-chip process, that is, the diode chip is separate and is bonded to the circuit substrate by artificial assembly using conductive adhesive and other materials. Therefore, in the traditional frequency multiplier, only a small part of the diode is connected to the external cavity. Since the external cavity is metal, the heat dissipation of the diode mainly depends on the heat conduction with the external cavity. Due to the small connection area with the metal, heat dissipation is difficult, and heat accumulation will further deteriorate the performance of the frequency multiplier.

[0049] In some embodiments, the diode pair 15 may be Schottky diodes connected in parallel in phase.

[0050] In some embodiments, the terahertz frequency multiplier 1 may include a micro-coaxial arched matching structure 18 for dissipating heat from the diode pair 15; the first end of the micro-coaxial arched matching structure 18 may be coaxially connected to the diode pair 15, and the micro-coaxial arched matching structure 18 may be coaxially connected to the transition structure 16 of the micro-coaxial output waveguide.

[0051] In some embodiments, the transition structure 16 of the micro-coaxial output waveguide may include an output probe 160, which may be formed by extending the inner conductor of the transition structure 16 of the micro-coaxial output waveguide toward the inside of the output waveguide 17, for impedance matching between the transition structure 16 of the micro-coaxial output waveguide and the output waveguide 17.

[0052] In some embodiments, the first end of the output probe 160 can be coaxially connected to the diode pair 15 through a micro-coaxial arch matching structure 18; the first end of the output waveguide 17 can be connected to the second end of the output probe 160, and the second end of the output waveguide 17 can be used to transmit the output signal.

[0053] Therefore, in the embodiment of the present application, when the transition structure 16 of the micro-coaxial output waveguide transitions to the output waveguide 17, it is only necessary to extend the inner conductor outward, so the structure is simple and the circuit size is small.

[0054] In some embodiments, the input waveguide 13 and the output waveguide 17 may be rectangular waveguides.

[0055] In the present application, the input signal is fed into the input waveguide 13, transitioned through the input probe 120, the waveguide TE10 mode is converted into a quasi-TEM mode for transmission, and transmitted to the diode pair 15 through the micro-coaxial input low-pass filter 14 for frequency doubling amplification.

[0056] In the present application, two micro-coaxial matching circuits of the diode pair 15 of the terahertz frequency multiplier 1 and the input low-pass filter 14 of the micro-coaxial are designed through a micro-coaxial structure, so that no substrate structure can be used in the circuit, thereby reducing the loss introduced by the substrate. At the same time, due to the use of the input low-pass filter 14 of the micro-coaxial, the size of the entire circuit is also reduced, and miniaturization is achieved. In addition, since the inner conductor lead-out direct connection structure 11 adopts a micro-coaxial structure, the DC bias circuit can be directly fed with DC from the inner conductor through the SMA coaxial line, thereby eliminating the traditional DC filter circuit, which reduces the complexity of the circuit on the one hand, and avoids the complex transformation of the traditional mixer quartz substrate-5880 soft substrate-coaxial line on the other hand, further reducing the circuit loss.

[0057] The above is only the preferred embodiment of the present application. Those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present application. In addition, under the guidance of the present application, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application belong to the protection scope of the present application.

Claims

1. A terahertz frequency multiplier, characterized in that: include: An inner conductor lead-out direct connection structure, a transition structure of a micro-coaxial input waveguide, an input waveguide for receiving an input signal, a micro-coaxial input low-pass filter for filtering the input signal, a diode pair for frequency-multiplying and amplifying the filtered input signal to generate an output signal, a transition structure of a micro-coaxial output waveguide, two micro-coaxial matching circuits, and an output waveguide for transmitting the output signal; The first end of the inner conductor lead-out direct connection structure is directly connected to an external DC bias circuit through the inner conductor of the micro-coaxial, and the second end of the inner conductor lead-out direct connection structure is coaxially connected to the transition structure of the input waveguide of the micro-coaxial, and the inner conductor lead-out direct connection structure is used to introduce the bias voltage of the external DC bias circuit to reduce distortion; The first end of the transition structure of the micro-coaxial input waveguide is coaxially connected to the second end of the inner conductor lead-out direct connection structure, the second end of the transition structure of the micro-coaxial input waveguide is connected to the input waveguide, and the third end of the transition structure of the micro-coaxial input waveguide is coaxially connected to the input low-pass filter of the micro-coaxial; The first end of the diode pair is coaxially connected to the input low-pass filter of the micro-coaxial through one of the micro-coaxial matching circuits, and the second end of the diode pair is coaxially connected to the first end of the transition structure of the output waveguide of the micro-coaxial through another of the micro-coaxial matching circuits, wherein the second end of the transition structure of the output waveguide of the micro-coaxial is connected to the output waveguide.

2. The terahertz frequency multiplier according to claim 1, characterized in that: The transition structure of the micro-coaxial input waveguide includes an input probe, which is formed by extending toward the inside of the input waveguide through an inner conductor of the transition structure of the micro-coaxial input waveguide, and is used for impedance matching between the transition structure of the micro-coaxial input waveguide and the input waveguide.

3. The terahertz frequency multiplier according to claim 2, characterized in that: The first end of the input waveguide is used to receive the input signal, and the second end of the input waveguide is connected to the input probe; the first end of the input probe is coaxially connected to the second end of the inner conductor lead-out direct connection structure, the second end of the input probe is connected to the second end of the input waveguide, and the third end of the input probe is coaxially connected to the first end of the micro-coaxial input low-pass filter.

4. The terahertz frequency multiplier according to claim 1, characterized in that: The diode pair is directly connected to the inner conductor of the micro-coaxial matching circuit at both ends of the diode pair.

5. The terahertz frequency multiplier according to claim 1, characterized in that: The inner conductor of the micro-coaxial input low-pass filter includes a plurality of rectangular branches.

6. The terahertz frequency multiplier according to claim 1, characterized in that: The terahertz frequency multiplier comprises a micro-coaxial arched matching structure for heat dissipation of the diode pair; a first end of the micro-coaxial arched matching structure is coaxially connected to the diode pair, and the micro-coaxial arched matching structure is coaxially connected to a transition structure of an output waveguide of the micro-coaxial.

7. The terahertz frequency multiplier according to claim 1, characterized in that: The diode pair is Schottky diodes connected in parallel in phase.

8. The terahertz frequency multiplier according to claim 6, characterized in that: The transition structure of the micro-coaxial output waveguide includes an output probe, which is formed by extending toward the inside of the output waveguide through an inner conductor of the transition structure of the micro-coaxial output waveguide, and is used for impedance matching between the transition structure of the micro-coaxial output waveguide and the output waveguide.

9. The terahertz frequency multiplier according to claim 8, characterized in that: The first end of the output probe is coaxially connected to the diode pair through the arch matching structure of the micro-coaxial; the first end of the output waveguide is connected to the second end of the output probe, and the second end of the output waveguide is used to output the output signal.

10. The terahertz frequency multiplier according to claim 1, characterized in that: The external DC bias circuit directly leads out the inner conductor of the direct connection structure from the inner conductor through the SMA coaxial line to perform DC feeding on the terahertz frequency multiplier.

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