A terahertz power combining circuit

Abstract

This application discloses a terahertz power combining circuit, including a microcoaxial input power divider circuit, a microcoaxial output power combiner, and two microcoaxial frequency multipliers. The microcoaxial input power divider circuit receives an input signal and splits it into two local oscillator signals, which are then transmitted to the microcoaxial frequency multipliers. The microcoaxial frequency multipliers amplify the local oscillator signals to obtain frequency-doubled local oscillator signals, and transmit the two frequency-doubled local oscillator signals to the microcoaxial output power combiner. The microcoaxial output power combiner combines the two frequency-doubled local oscillator signals to obtain the output signal. This application's embodiment, based on a microcoaxial structure, achieves high isolation, thereby reducing interference between different branches and improving frequency doubling efficiency. Furthermore, it avoids repeated waveguide-probe transition structures, further reducing losses and improving frequency doubling efficiency, thus increasing the overall output power of the terahertz power combining circuit.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a terahertz power combining circuit. Background Technology

[0002] For applications in the terahertz frequency band, a high-quality terahertz frequency source is crucial for terahertz system applications, and its performance largely determines the system's performance. Currently, terahertz solid-state frequency sources are developing towards higher frequencies, higher power, wider bandwidths, monolithic integration, and ultra-low phase noise.

[0003] To achieve higher power output, power combining circuits based on waveguides (such as Y-type power dividers and couplers) are often used. Connecting waveguide circuits to terahertz frequency multipliers requires repeated use of waveguide-to-microstrip transition structures, which greatly increases circuit losses and degrades circuit performance.

[0004] Meanwhile, because traditional T-type power dividers are often not matched to each port, the isolation between the two output ports is poor, typically between 5-8 dB. In power combining networks, severe interference between different branches degrades power combining efficiency and affects the output power of the terahertz source. Summary of the Invention

[0005] The purpose of this application is to provide a terahertz power combining circuit to solve the technical problems of excessive circuit loss and poor isolation in existing terahertz power combining circuits. The preferred technical solutions among the various technical solutions provided in this application and their numerous technical effects are detailed below.

[0006] To achieve the above objectives, this application provides the following technical solutions:

[0007] This application provides a terahertz power combining circuit, including a microcoaxial input power divider circuit, a microcoaxial output power combiner, and two microcoaxial frequency multipliers. The microcoaxial input power divider circuit receives an input signal and splits it into two local oscillator signals, which are then transmitted to the microcoaxial frequency multipliers. The microcoaxial frequency multipliers amplify the local oscillator signals to obtain frequency-doubled local oscillator signals, and transmit the two frequency-doubled local oscillator signals to the microcoaxial output power combiner. The microcoaxial output power combiner combines the two frequency-doubled local oscillator signals to obtain an output signal. The first output port of the input power divider circuit of the microcoaxial axis is coaxially connected to the receiving end of one of the microcoaxial frequency multipliers; the second output port of the input power divider circuit of the microcoaxial axis is coaxially connected to the receiving end of another microcoaxial frequency multiplier; the second input port of the output power combiner of the microcoaxial axis is coaxially connected to the output end of one of the microcoaxial frequency multipliers; the third input port of the output power combiner of the microcoaxial axis is coaxially connected to the output end of another microcoaxial frequency multiplier; the two microcoaxial frequency multipliers are symmetrically arranged with respect to the input power divider circuit and the output power combiner of the microcoaxial axis.

[0008] In some embodiments, the micro coaxial input power divider circuit includes a first input port, a first isolation port, and a second isolation port; the first output port and the second output port are symmetrically arranged with respect to the first input port, and the first isolation port and the second isolation port are symmetrically arranged with respect to the first input port; the first input port is used to receive the input signal.

[0009] In some embodiments, the microcoaxial input power divider circuit includes a first input waveguide, a first output waveguide, a second output waveguide, a first isolation waveguide, a second isolation waveguide, and a first transition waveguide. One end of the first input waveguide is the first input port, and the other end is connected to the first end of the first transition waveguide. The first input waveguide, the first isolation waveguide, and the second isolation waveguide are all oriented in the same direction, and the first input waveguide is perpendicular to the first transition waveguide, the first output waveguide, and the second output waveguide.

[0010] In some embodiments, the second end of the first transition waveguide of the microcoaxial cable is coaxially connected to one end of the first output waveguide of the microcoaxial cable and one end of the first isolation waveguide of the microcoaxial cable, wherein the other end of the first output waveguide of the microcoaxial cable is the first output port and the other end of the first isolation waveguide of the microcoaxial cable is the first isolation port; the third end of the first transition waveguide of the microcoaxial cable is coaxially connected to one end of the second output waveguide of the microcoaxial cable and one end of the second isolation waveguide of the microcoaxial cable, wherein the other end of the second output waveguide of the microcoaxial cable is the second output port and the other end of the second isolation waveguide of the microcoaxial cable is the second isolation port.

[0011] In some embodiments, the micro-coaxial output power combiner includes a third output port, a third isolation port, and a fourth isolation port; the second input port and the third input port are symmetrically arranged with respect to the third output port, and the third isolation port and the fourth isolation port are symmetrically arranged with respect to the third output port; the third output port is used to feed the output signal.

[0012] In some embodiments, the microcoaxial output power combiner includes a second input waveguide, a third input waveguide, a third output waveguide, a third isolation waveguide, a fourth isolation waveguide, and a second transition waveguide of the microcoaxial system. One end of the third output waveguide is the third output port, and the other end is connected to the first end of the second transition waveguide. The third output waveguide, the third isolation waveguide, and the fourth isolation waveguide are all oriented in the same direction, and the third output waveguide is perpendicular to the second input waveguide, the third input waveguide, and the second transition waveguide.

[0013] In some embodiments, the microcoaxial frequency multiplier includes an inner conductor lead-out direct connection structure, a transition structure of the fourth input waveguide of the microcoaxial circuit, a fourth input waveguide of the microcoaxial circuit for receiving the local oscillator signal, an input low-pass filter of the microcoaxial circuit for filtering the local oscillator signal, a pair of diodes for frequency multiplication and amplification of the filtered local oscillator signal to generate a frequency-doubled local oscillator signal, a transition structure of the fourth output waveguide of the microcoaxial circuit, two microcoaxial matching circuits, and a fourth output waveguide of the microcoaxial circuit for feeding the frequency-doubled local oscillator 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 microcoaxial circuit, and the second end of the inner conductor lead-out direct connection structure is coaxially connected to the transition structure of the fourth input waveguide of the microcoaxial circuit. The inner conductor lead-out direct connection structure is used to introduce the bias voltage of the external DC bias circuit to reduce distortion.

[0014] In some embodiments, the first end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the second end of the direct connection structure of the inner conductor; the second end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the fourth input waveguide of the microcoaxial cable; and the third end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the input low-pass filter of the microcoaxial cable. The first end of the diode pair is coaxially connected to the input low-pass filter of the microcoaxial cable through one of the microcoaxial matching circuits, and the second end of the diode pair is coaxially connected to the first end of the transition structure of the fourth output waveguide of the microcoaxial cable through another of the microcoaxial matching circuits, wherein the second end of the transition structure of the fourth output waveguide of the microcoaxial cable is coaxially connected to the fourth output waveguide of the microcoaxial cable.

[0015] In some embodiments, the transition structure of the fourth input waveguide of the microcoaxial cable includes an input probe that extends into the interior of the fourth input waveguide of the microcoaxial cable through an inner conductor of the transition structure, for impedance matching between the transition structure of the fourth input waveguide of the microcoaxial cable and the fourth input waveguide of the microcoaxial cable.

[0016] In some embodiments, the first end of the fourth input waveguide of the micro-coaxial cable is the receiving end of the micro-coaxial frequency multiplier for receiving the local oscillator signal; the second end of the fourth input waveguide of the micro-coaxial cable is coaxially connected to the input probe; the first end of the input probe is coaxially connected to the second end of the direct connection structure of the inner conductor; the second end of the input probe is coaxially connected to the second end of the fourth input waveguide of the micro-coaxial cable; and the third end of the input probe is coaxially connected to the first end of the input low-pass filter of the micro-coaxial cable.

[0017] Implementing one of the above-described technical solutions of this application has the following advantages or beneficial effects: In this application, by setting an input power divider circuit and an output power combiner of a micro-coaxial structure, the input signal is split into two local oscillator signals and sent to a micro-coaxial frequency multiplier for frequency multiplication and amplification, and then power combined to obtain the output signal. On the one hand, due to the closed characteristics of the inner conductor of the micro-coaxial structure, the embodiments of this application achieve a high degree of isolation based on the micro-coaxial structure connection, with an isolation level of over 20dB, thereby reducing interference between different branches and improving the frequency multiplication efficiency of the overall terahertz power combining circuit; on the other hand, the input power divider circuit and the output power combiner based on the micro-coaxial structure can be directly connected to the micro-coaxial frequency multiplier, avoiding repeated waveguide-probe transition structures, further reducing losses, improving frequency multiplication efficiency, and thus improving the output power of the overall terahertz power combining circuit. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0019] Figure 1 This is a schematic diagram of a terahertz power combining circuit according to an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of the structure of the micro coaxial transmission line according to an embodiment of this application;

[0021] Figure 3 This is another schematic diagram of the terahertz power combining circuit according to an embodiment of this application;

[0022] Figure 4 This is a schematic diagram of the structure of the inner conductor of the terahertz power combining circuit according to an embodiment of this application;

[0023] Figure 5 This is a schematic diagram of the inner conductor of the input power divider circuit of the micro coaxial cable according to an embodiment of this application;

[0024] Figure 6 This is a schematic diagram of the structure of the micro coaxial frequency multiplier according to an embodiment of this application;

[0025] Figure 7 This is a schematic diagram of the inner conductor of the micro-coaxial frequency multiplier according to an embodiment of this application.

[0026] In the diagram: 1. Terahertz power combining circuit; 2. Micro-coaxial input power divider circuit; 3. Micro-coaxial output power combiner; 4. Micro-coaxial frequency multiplier;

[0027] 20. First output port; 21. Second output port; 22. First input port; 23. First input waveguide of microcoaxial cable; 24. First output waveguide of microcoaxial cable; 25. Second output waveguide of microcoaxial cable; 26. First isolation waveguide of microcoaxial cable; 27. Second isolation waveguide of microcoaxial cable; 28. First transition waveguide of microcoaxial cable;

[0028] 30. Second input port; 31. Third input port; 32. Third output port; 33. Second input waveguide of the microcoaxial cable; 34. Third input waveguide of the microcoaxial cable; 35. Third output waveguide of the microcoaxial cable; 36. Third isolation waveguide of the microcoaxial cable; 37. Fourth isolation waveguide of the microcoaxial cable; 38. Second transition waveguide of the microcoaxial cable;

[0029] 41. Inner conductor lead-out direct connection structure; 42. Transition structure of the fourth input waveguide of the micro-coaxial cable; 43. Fourth input waveguide; 44. Input low-pass filter of the micro-coaxial cable; 45. Diode pair; 46. Transition structure of the fourth output waveguide of the micro-coaxial cable; 47. Fourth output waveguide; 420. Input probe; 460. Output probe;

[0030] 11. First turning waveguide of the microcoaxial line; 12. Second turning waveguide of the microcoaxial line; 13. Third turning waveguide of the microcoaxial line; 14. Fourth turning waveguide of the microcoaxial line; 15. Fifth turning waveguide of the microcoaxial line; 16. Sixth turning waveguide of the microcoaxial line. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments and depict various exemplary embodiments that may be adopted to implement this application. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of this application disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of this application.

[0032] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the referred element must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. The term "multiple" means two or more. The terms "connected" and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections 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 of the related listed items. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] To illustrate the technical solutions described in this application, specific embodiments are provided below, showing only the parts related to the embodiments of this application.

[0034] like Figure 1 As shown, this application provides a terahertz power combining circuit 1, which may include a micro-coaxial input power divider circuit 2, a micro-coaxial output power combiner 3, and two micro-coaxial frequency multipliers 4.

[0035] In some embodiments, the input power divider circuit 2 of the micro coaxial circuit can receive the input signal and divide the input signal into two local oscillator signals for transmission to the micro coaxial frequency multiplier 4.

[0036] In some embodiments, the micro coaxial frequency multiplier 4 can multiply and amplify the local oscillator signal to obtain a frequency-doubled local oscillator signal, and transmit the two frequency-doubled local oscillator signals to the output power combiner 3 of the micro coaxial circuit.

[0037] In some embodiments, the micro coaxial output power combiner 3 can combine the power of two frequency-doubled local oscillator signals to obtain an output signal.

[0038] In some embodiments, the terahertz power combining circuit 1 can transmit signals via a rectangular micro coaxial cable. For example... Figure 2 As shown, a rectangular micro coaxial cable may include an inner conductor, a dielectric support, and an outer shielding cavity. Specifically, the inner conductor may be a closed structure, and it may be disposed inside the outer shielding cavity. A dielectric support is disposed between the inner conductor and the outer shielding cavity, and signals can be transmitted through the inner conductor.

[0039] In some embodiments, the transmission mode of the rectangular microcoaxial cable is TEM mode. Therefore, using the rectangular microcoaxial cable for transmission has the advantages of low dispersion and low loss, enabling the terahertz power combining circuit 1 to operate over a wider operating frequency range.

[0040] In summary, traditional rectangular waveguides exhibit high-pass characteristics, but fixed-size rectangular waveguides can only transmit electromagnetic waves within a fixed frequency band and cannot achieve broadband transmission. Meanwhile, because the inner conductor of a rectangular microcoaxial cable is closed, it offers high isolation. Even when two rectangular microcoaxial cables are very close together, their mutual interference is minimal, allowing for very close wiring. Impedance can be easily altered by adjusting the dimensions of the inner conductor. Furthermore, the performance of rectangular microcoaxial cables is unaffected by bending and cross-coupling, facilitating the construction of complex circuits and devices, thereby enabling high-level integration of circuit systems.

[0041] In some embodiments, such as Figure 3 As shown, the first output port 20 of the micro-coaxial input power divider circuit 2 can be coaxially connected to the receiving end of a micro-coaxial frequency multiplier 4, and the second output port 21 of the micro-coaxial input power divider circuit 2 is coaxially connected to the receiving end of another micro-coaxial frequency multiplier 4.

[0042] In some embodiments, such as Figure 4As shown, the second input port 30 of the micro-coaxial output power combiner 3 can be coaxially connected to the output of a micro-coaxial frequency multiplier 4, and the third input port 31 of the micro-coaxial output power combiner 3 can be coaxially connected to the output of another micro-coaxial frequency multiplier 4.

[0043] In some embodiments, the two microcoaxial frequency multipliers 4 can be symmetrically arranged with respect to the input power divider circuit 2 of the microcoaxial circuit and the output power combiner 3 of the microcoaxial circuit.

[0044] The coaxial connection in this application embodiment can refer to the direct connection of the inner conductors of a micro-coaxial cable.

[0045] In some embodiments, such as Figure 5 As shown, the micro-coaxial input power divider circuit 2 may include a first input port 22, a first output port 20, a second output port 21, a first isolation port, and a second isolation port. The first output port 20 and the second output port 21 may be symmetrically arranged with respect to the first input port 22, and the first isolation port and the second isolation port may be symmetrically arranged with respect to the first input port 22. The first input port 22 can be used to receive input signals.

[0046] In some embodiments, the first input port 22 can be used to receive an input signal, the first output port 20 and the second output port 21 can be used to output a local oscillator signal to the corresponding micro coaxial frequency multiplier 4, and the first isolation port and the second isolation port can be used for signal isolation. The first output port 20 can be coaxially connected to one micro coaxial frequency multiplier 4, and the second output port 21 can be coaxially connected to another micro coaxial frequency multiplier 4.

[0047] In some embodiments, the microcoaxial input power divider circuit 2 may include a microcoaxial first input waveguide 23, a microcoaxial first output waveguide 24, a microcoaxial second output waveguide 25, a microcoaxial first isolation waveguide 26, a microcoaxial second isolation waveguide 27, and a microcoaxial first transition waveguide 28.

[0048] In some embodiments, one end of the first input waveguide 23 of the microcoaxial can be the first input port 22, and the other end of the first input waveguide 23 of the microcoaxial can be connected to the first end of the first transition waveguide 28 of the microcoaxial.

[0049] In some embodiments, the first input waveguide 23 of the microcoaxial can be oriented in the same direction as the first isolation waveguide 26 and the second isolation waveguide 27 of the microcoaxial, and the first input waveguide 23 of the microcoaxial can be oriented perpendicularly to the first transition waveguide 28, the first output waveguide 24 and the second output waveguide 25 of the microcoaxial.

[0050] In some embodiments, the second end of the first transition waveguide 28 of the microcoaxial can be coaxially connected to one end of the first output waveguide 24 of the microcoaxial and one end of the first isolation waveguide 26 of the microcoaxial, wherein the other end of the first output waveguide 24 of the microcoaxial can be the first output port 20, and the other end of the first isolation waveguide 26 of the microcoaxial can be the first isolation port; the third end of the first transition waveguide 28 of the microcoaxial can be coaxially connected to one end of the second output waveguide 25 of the microcoaxial and one end of the second isolation waveguide 27 of the microcoaxial, wherein the other end of the second output waveguide 25 of the microcoaxial can be the second output port 21, and the other end of the second isolation waveguide 27 of the microcoaxial can be the second isolation port.

[0051] In some embodiments, the interior of the first isolation waveguide 26 and the second isolation waveguide 27 of the microcoaxial can be filled with absorbing material, and the inner conductors of the first isolation waveguide 26 and the second isolation waveguide 27 of the microcoaxial do not need to extend to the first isolation port and the second isolation port.

[0052] In some embodiments, the terahertz power combining circuit 1 may include a first microcoaxial turning waveguide 11 and a second microcoaxial turning waveguide 12.

[0053] In some embodiments, one end of the first microcoaxial turning waveguide 11 can be coaxially connected to the first output port 20, and the other end of the first microcoaxial turning waveguide 11 can be coaxially connected to a microcoaxial frequency multiplier 4. One end of the second microcoaxial turning waveguide 12 can be coaxially connected to the second output port 21, and the other end of the second microcoaxial turning waveguide 12 can be coaxially connected to another microcoaxial frequency multiplier 4. The first microcoaxial turning waveguide 11 and the second microcoaxial turning waveguide 12 can be used to transmit the local oscillator signal to the corresponding microcoaxial frequency multiplier 4.

[0054] In some embodiments, impedance matching can be performed at the connection between the first turning waveguide 11 and the first output port 20 of the microcoaxial cable, and at the connection between the second turning waveguide 12 and the second output port 21 of the microcoaxial cable. The inner conductor size of the first output waveguide 24 of the microcoaxial cable can be larger than the inner conductor size of the first turning waveguide 11 of the microcoaxial cable, and the inner conductor size of the second output waveguide 25 of the microcoaxial cable can be larger than the inner conductor size of the second turning waveguide 12 of the microcoaxial cable. The first turning waveguide 11 and the second turning waveguide 12 of the microcoaxial cable can be symmetrically arranged with respect to the input power divider circuit 2 of the microcoaxial cable.

[0055] In some embodiments, the micro-coaxial output power combiner 3 may include a second input port 30, a third input port 31, a third output port 32, a third isolation port, and a fourth isolation port. The second input port 30 may be symmetrically arranged with respect to the third input port 31 about the third output port 32, and the third isolation port may be symmetrically arranged with respect to the fourth isolation port about the third output port 32; the third output port 32 may be used to feed an output signal.

[0056] In some embodiments, the second input port 30 and the third input port 31 can be used to receive the frequency-doubled local oscillator signal, and the third isolation port and the fourth isolation port can be used for signal isolation. The second input port 30 can be connected to a micro coaxial frequency multiplier 4, and the third input port 31 can be connected to another micro coaxial frequency multiplier 4.

[0057] In some embodiments, the microcoaxial output power combiner 3 may include a second input waveguide 33 of the microcoaxial, a third input waveguide 34 of the microcoaxial, a third output waveguide 35 of the microcoaxial, a third isolation waveguide 36 of the microcoaxial, a fourth isolation waveguide 37 of the microcoaxial, and a second transition waveguide 38 of the microcoaxial; one end of the third output waveguide 35 of the microcoaxial can be a third output port 32, and the other end of the third output waveguide 35 of the microcoaxial can be connected to the first end of the second transition waveguide 38 of the microcoaxial.

[0058] In some embodiments, the third output waveguide 35 of the microcoaxial can be oriented in the same direction as the third isolation waveguide 36 and the fourth isolation waveguide 37 of the microcoaxial, and the third output waveguide 35 of the microcoaxial can be oriented perpendicularly to the second input waveguide 33, the third input waveguide 34 and the second transition waveguide 38 of the microcoaxial.

[0059] In some embodiments, one end of the third output waveguide 35 of the microcoaxial can be the third output port 32 of the output power combiner 3 of the microcoaxial, and the other end of the third output waveguide 35 of the microcoaxial can be coaxially connected to the first end of the second transition waveguide 38 of the microcoaxial.

[0060] In some embodiments, the second end of the second transition waveguide 38 of the microcoaxial can be coaxially connected to one end of the second input waveguide 33 of the microcoaxial and one end of the third isolation waveguide 36 of the microcoaxial, wherein the other end of the second input waveguide 33 of the microcoaxial can be the second input port 30, and the other end of the third isolation waveguide 36 of the microcoaxial can be the third isolation port; the third end of the second transition waveguide 38 of the microcoaxial can be coaxially connected to one end of the third input waveguide 34 of the microcoaxial and one end of the fourth isolation waveguide 37 of the microcoaxial, wherein the other end of the third input waveguide 34 of the microcoaxial can be the third input port 31, and the other end of the fourth isolation waveguide 37 of the microcoaxial can be the fourth isolation port.

[0061] In some embodiments, the terahertz power combining circuit 1 may include a microcoaxial third turning waveguide 13, a microcoaxial fourth turning waveguide 14, a microcoaxial fifth turning waveguide 15, and a microcoaxial sixth turning waveguide 16.

[0062] In some embodiments, one end of the third turning waveguide 13 of the micro-coaxial can be coaxially connected to the second input port 30, and the other end of the third turning waveguide 13 of the micro-coaxial can be coaxially connected to one end of the fifth turning waveguide 15 of the micro-coaxial, wherein the other end of the fifth turning waveguide 15 of the micro-coaxial is connected to a micro-coaxial frequency multiplier 4.

[0063] In some embodiments, one end of the fourth turning waveguide 14 of the microcoaxial cable can be coaxially connected to the third input port 31, and the other end of the fourth turning waveguide 14 of the microcoaxial cable can be connected to one end of the sixth turning waveguide 16 of the microcoaxial cable, wherein the other end of the sixth turning waveguide 16 of the microcoaxial cable can be connected to another microcoaxial frequency multiplier 4. The third turning waveguide 13 and the fifth turning waveguide 15 of the microcoaxial cable, as well as the fourth turning waveguide 14 and the sixth turning waveguide 16 of the microcoaxial cable, can be used to transmit the two frequency-doubled local oscillator signals to the output power combiner 3 of the microcoaxial cable.

[0064] In some embodiments, the third turning waveguide 13 and the fourth turning waveguide 14 of the microcoaxial can be symmetrically arranged with respect to the output power combiner 3 of the microcoaxial, and the fifth turning waveguide 15 and the sixth turning waveguide 16 of the microcoaxial can be symmetrically arranged with respect to the output power combiner 3 of the microcoaxial.

[0065] In some embodiments, the third turning waveguide 13 and the fifth turning waveguide 15 of the microcoaxial can be arranged in a centrally symmetrical manner, and the fourth turning waveguide 14 and the sixth turning waveguide 16 of the microcoaxial can be arranged in a centrally symmetrical manner.

[0066] In some embodiments, such as Figure 6 As shown, the microcoaxial frequency multiplier 4 may include an inner conductor lead-out direct connection structure 41, a transition structure 42 for the fourth input waveguide of the microcoaxial, a fourth input waveguide 43 for receiving the local oscillator signal, an input low-pass filter 44 for filtering the local oscillator signal, a pair of diodes 45 for frequency multiplication and amplification of the filtered local oscillator signal to generate a frequency-doubled local oscillator signal, a transition structure 46 for the fourth output waveguide of the microcoaxial, two microcoaxial matching circuits, and a fourth output waveguide 47 for feeding the frequency-doubled local oscillator signal.

[0067] In some embodiments, the first end of the inner conductor lead-out direct connection structure 41 can be directly connected to an external DC bias circuit through the inner conductor of the micro-coaxial circuit, and the second end of the inner conductor lead-out direct connection structure 41 can be coaxially connected to the transition structure 42 of the fourth input waveguide of the micro-coaxial circuit. The inner conductor lead-out direct connection structure 41 can be used to introduce the bias voltage of the external DC bias circuit to reduce distortion.

[0068] Traditional microstrip-based frequency multiplier structures often use quartz substrates or other materials, making it impossible for the inner conductor of the coaxial connector to connect directly. This necessitates the use of an additional 5880 flexible substrate for transition, increasing circuit size, connection losses, and overall fabrication complexity. In this embodiment, the inner conductor lead-out direct connection structure 41 can be formed by directly extending a rectangular microcoaxial line. Therefore, this embodiment offers advantages such as simple structure, convenient connection, low loss, and small size.

[0069] In some embodiments, the inner conductor of the inner conductor leading out direct connection structure 41 can extend from one end of the inner conductor leading out direct connection structure 41 to the other end. That is, the two ends of the inner conductor leading out direct connection structure 41 can be directly connected to the inner conductor of the inner conductor leading out direct connection structure 41.

[0070] In some embodiments, the first end of the transition structure 42 of the micro-coaxial fourth input waveguide can be coaxially connected to the second end of the inner conductor lead-out direct connection structure 41, the second end of the transition structure 42 of the micro-coaxial fourth input waveguide can be coaxially connected to the micro-coaxial fourth input waveguide 43, and the third end of the transition structure 42 of the micro-coaxial fourth input waveguide can be coaxially connected to the micro-coaxial input low-pass filter 44.

[0071] In some embodiments, the first end of the diode pair 45 can be coaxially connected to the input low-pass filter 44 of the microcoaxial via a microcoaxial matching circuit, and the second end of the diode pair 45 can be coaxially connected to the first end of the transition structure 46 of the fourth output waveguide of the microcoaxial via another microcoaxial matching circuit, wherein the second end of the transition structure 46 of the fourth output waveguide of the microcoaxial can be coaxially connected to the fourth output waveguide 47 of the microcoaxial.

[0072] In some embodiments, such as Figure 7 As shown, the transition structure 42 of the fourth input waveguide of the microcoaxial cable may include an input probe 420. The input probe 420 can be formed by extending the inner conductor of the transition structure 42 into the interior of the fourth input waveguide 43 of the microcoaxial cable, for impedance matching between the transition structure 42 and the fourth input waveguide 43. Therefore, in this embodiment, when the transition structure 42 of the fourth input waveguide of the microcoaxial cable transitions to the input waveguide 43, only the inner conductor needs to be extended outwards, resulting in a simple structure and small circuit size.

[0073] In some embodiments, the first end of the fourth input waveguide 43 of the microcoaxial can be the receiving end of the microcoaxial frequency multiplier 4 for receiving the local oscillator signal, and the second end of the fourth input waveguide 43 of the microcoaxial can be connected to the input probe 420; the first end of the input probe 420 can be coaxially connected to the second end of the inner conductor lead-out direct connection structure 41, the second end of the input probe 420 can be coaxially connected to the second end of the fourth input waveguide 43 of the microcoaxial, and the third end of the input probe 420 can be coaxially connected to the first end of the input low-pass filter 44 of the microcoaxial.

[0074] In some embodiments, the inner conductor of the micro-coaxial input low-pass filter 44 may include multiple rectangular branches. Specifically, the inner conductor of the micro-coaxial input low-pass filter 44 may extend in a direction perpendicular to the inner conductor's extension direction to form multiple rectangular branches. This allows for impedance variation, thereby achieving the performance of a resonant cavity and satisfying the filtering effect.

[0075] In some embodiments, the first terminal of diode pair 45 can be coaxially connected to the input low-pass filter 44 of the microcoaxial cable via a microcoaxial matching circuit, and the second terminal of diode pair 45 can be coaxially connected to the first terminal of the transition structure 46 of the fourth output waveguide of the microcoaxial cable via another microcoaxial matching circuit. The second terminal of the transition structure 46 of the fourth output waveguide of the microcoaxial cable can be connected to one end of the fourth output waveguide 47, the other end of which is the output terminal of the microcoaxial frequency multiplier 4. The inner conductor of one microcoaxial matching circuit can be directly connected to the inner conductor of the input low-pass filter 44 of the microcoaxial cable, and the other microcoaxial matching circuit can be directly connected to the inner conductor of the transition structure 46 of the fourth output waveguide of the microcoaxial cable.

[0076] In some embodiments, diode pair 45 can be directly connected to the inner conductor of the micro-coaxial matching circuit across diode pair 45. In this case, multiple coaxial-to-microstrip line transitions can be omitted, making the circuit structure of micro-coaxial frequency multiplier 4 more compact; the heat dissipation area of ​​diode pair 45 can be increased, reducing the impact of heat accumulation on the performance of micro-coaxial frequency multiplier 4.

[0077] In some embodiments, the transition structure of the output waveguide of the microcoaxial may include an output probe 460, which may be formed by extending the inner conductor of the transition structure 46 of the fourth output waveguide of the microcoaxial into the interior of the fourth output waveguide 47 for impedance matching between the transition structure 46 and the fourth output waveguide 47 of the microcoaxial.

[0078] Therefore, in the embodiments of this application, when the transition structure 46 of the micro coaxial output waveguide transitions to the output waveguide 47, only the inner conductor needs to be extended outward, so the structure is simple and the circuit size is small.

[0079] In some embodiments, the second ends of the two fourth output waveguides 47 are coaxially connected to the micro-coaxial output power combiner 3, respectively, for transmitting two frequency-doubled local oscillator signals to the micro-coaxial output power combiner 3.

[0080] In this application, by setting up an input power divider circuit 2 and an output power combiner for the micro-coaxial circuit, the input signal is split into two local oscillator signals and sent to the micro-coaxial frequency multiplier 4 for frequency multiplication and amplification, and then the signals are combined to obtain the output signal. On the one hand, due to the closed characteristics of the inner conductor of the micro-coaxial circuit, the embodiment of this application achieves a high degree of isolation based on the micro-coaxial structure connection, with an isolation level of over 20dB, thereby reducing interference between different branches and improving the frequency multiplication efficiency of the overall terahertz power combining circuit 1. On the other hand, the input power divider circuit and the output power combiner based on the micro-coaxial structure can be directly connected to the micro-coaxial frequency multiplier 4, avoiding repeated waveguide-probe transition structures, further reducing losses, improving frequency multiplication efficiency, and thus increasing the output power of the overall terahertz power combining circuit 1.

[0081] The above description is merely a preferred embodiment of this application. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this application. Furthermore, under the teachings of this application, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this application. Therefore, this application is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this application.

Claims

1. A terahertz power combining circuit, characterized in that, The system includes a microcoaxial input power divider circuit, a microcoaxial output power combiner, and two microcoaxial frequency multipliers. The microcoaxial input power divider circuit receives an input signal and splits it into two local oscillator signals, which are then transmitted to the microcoaxial frequency multipliers. The microcoaxial frequency multipliers amplify the local oscillator signals by frequency multiplication to obtain frequency-doubled local oscillator signals, and transmit the two frequency-doubled local oscillator signals to the microcoaxial output power combiner. The microcoaxial output power combiner combines the two frequency-doubled local oscillator signals to obtain an output signal. The first output port of the input power divider circuit of the micro-coaxial cable is coaxially connected to the receiving end of one of the micro-coaxial frequency multipliers, and the second output port of the input power divider circuit of the micro-coaxial cable is coaxially connected to the receiving end of another micro-coaxial frequency multiplier. The second input port of the output power combiner of the micro-coaxial circuit is coaxially connected to the output terminal of one of the micro-coaxial frequency multipliers, and the third input port of the output power combiner of the micro-coaxial circuit is coaxially connected to the output terminal of another micro-coaxial frequency multiplier. The two micro-coaxial frequency multipliers are symmetrically arranged with respect to the input power divider circuit of the micro-coaxial circuit and the output power combiner of the micro-coaxial circuit. The micro-coaxial input power divider circuit includes a first input port, a first isolation port, and a second isolation port; the first output port and the second output port are symmetrically arranged about the first input port, and the first isolation port and the second isolation port are symmetrically arranged about the first input port; the first input port is used to receive the input signal. The microcoaxial input power divider circuit includes a first input waveguide of the microcoaxial, a first output waveguide of the microcoaxial, a second output waveguide of the microcoaxial, a first isolation waveguide of the microcoaxial, a second isolation waveguide of the microcoaxial, and a first transition waveguide of the microcoaxial. One end of the first input waveguide of the microcoaxial cable is the first input port, and the other end of the first input waveguide of the microcoaxial cable is connected to the first end of the first transition waveguide of the microcoaxial cable. The first input waveguide of the microcoaxial cable has the same orientation as the first isolation waveguide and the second isolation waveguide of the microcoaxial cable, and the first input waveguide of the microcoaxial cable is perpendicular to the orientation of the first transition waveguide, the first output waveguide and the second output waveguide of the microcoaxial cable. The second end of the first transition waveguide of the microcoaxial cable is coaxially connected to one end of the first output waveguide of the microcoaxial cable and one end of the first isolation waveguide of the microcoaxial cable, wherein the other end of the first output waveguide of the microcoaxial cable is the first output port, and the other end of the first isolation waveguide of the microcoaxial cable is the first isolation port; the third end of the first transition waveguide of the microcoaxial cable is coaxially connected to one end of the second output waveguide of the microcoaxial cable and one end of the second isolation waveguide of the microcoaxial cable, wherein the other end of the second output waveguide of the microcoaxial cable is the second output port, and the other end of the second isolation waveguide of the microcoaxial cable is the second isolation port. The microcoaxial frequency multiplier includes an inner conductor lead-out direct connection structure, a transition structure for the fourth input waveguide of the microcoaxial circuit, a fourth input waveguide of the microcoaxial circuit for receiving the local oscillator signal, an input low-pass filter of the microcoaxial circuit for filtering the local oscillator signal, a pair of diodes for frequency multiplication and amplification of the filtered local oscillator signal to generate a frequency-doubled local oscillator signal, a transition structure for the fourth output waveguide of the microcoaxial circuit, two microcoaxial matching circuits, and a fourth output waveguide of the microcoaxial circuit for feeding the frequency-doubled local oscillator signal. The first end of the inner conductor lead-out direct connection structure is directly connected to the external DC bias circuit through the inner conductor of the micro-coaxial cable. The second end of the inner conductor lead-out direct connection structure is coaxially connected to the transition structure of the fourth input waveguide of the micro-coaxial cable. The inner conductor lead-out direct connection structure is used to introduce the bias voltage of the external DC bias circuit to reduce distortion.

2. The terahertz power combining circuit according to claim 1, characterized in that, The micro-coaxial output power combiner includes a third output port, a third isolation port, and a fourth isolation port; the second input port and the third input port are symmetrically arranged about the third output port, and the third isolation port and the fourth isolation port are symmetrically arranged about the third output port; the third output port is used to feed the output signal.

3. The terahertz power combining circuit according to claim 2, characterized in that, The output power combiner of the microcoaxial cable includes a second input waveguide, a third input waveguide, a third output waveguide, a third isolation waveguide, a fourth isolation waveguide, and a second transition waveguide. One end of the third output waveguide is the third output port, and the other end is connected to the first end of the second transition waveguide. The third output waveguide of the microcoaxial cable is oriented in the same direction as the third isolation waveguide and the fourth isolation waveguide of the microcoaxial cable. The third output waveguide of the microcoaxial cable is oriented perpendicularly to the second input waveguide, the third input waveguide, and the second transition waveguide of the microcoaxial cable.

4. The terahertz power combining circuit according to claim 1, characterized in that, The first end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the second end of the direct connection structure of the inner conductor; the second end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the fourth input waveguide of the microcoaxial cable; and the third end of the transition structure of the fourth input waveguide of the microcoaxial cable is coaxially connected to the input low-pass filter of the microcoaxial cable. The first end of the diode pair is coaxially connected to the input low-pass filter of the microcoaxial circuit through one of the microcoaxial matching circuits, and the second end of the diode pair is coaxially connected to the first end of the transition structure of the fourth output waveguide of the microcoaxial circuit through another of the microcoaxial matching circuits, wherein the second end of the transition structure of the fourth output waveguide of the microcoaxial circuit is coaxially connected to the fourth output waveguide of the microcoaxial circuit.

5. The terahertz power combining circuit according to claim 1, characterized in that, The transition structure of the fourth input waveguide of the microcoaxial cable includes an input probe, which extends into the interior of the fourth input waveguide of the microcoaxial cable through the inner conductor of the transition structure, for impedance matching between the transition structure of the fourth input waveguide of the microcoaxial cable and the fourth input waveguide of the microcoaxial cable.

6. The terahertz power combining circuit according to claim 5, characterized in that, The first end of the fourth input waveguide of the micro-coaxial cable is the receiving end of the micro-coaxial frequency multiplier, used to receive the local oscillator signal. The second end of the fourth input waveguide of the micro-coaxial cable is coaxially connected to the input probe. The first end of the input probe is coaxially connected to the second end of the direct connection structure of the inner conductor. The second end of the input probe is coaxially connected to the second end of the fourth input waveguide of the micro-coaxial cable. The third end of the input probe is coaxially connected to the first end of the input low-pass filter of the micro-coaxial cable.

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