A Terahertz Wideband Combiner Based on Gap Waveguide

Abstract

The present invention belongs to the technical field of microelectromechanical manufacturing, and particularly relates to a terahertz broadband combiner based on a gap waveguide, comprising: a first standard waveguide port for inputting a terahertz low-frequency signal, a second standard waveguide port for inputting a terahertz high-frequency signal, a third combiner port for outputting a terahertz combined signal, three matching transition structures, two input ridge waveguide tapered transition structures, a low-pass filtering structure, a combined gap waveguide structure, and a combined ridge waveguide tapered transition structure. The terahertz broadband combiner based on a gap waveguide provided by the present invention has the advantages of a wide operating frequency band, low loss, and easy processing, and can effectively meet the requirements of terahertz system combination.

Description

Technical Field

[0001] The present invention belongs to the technical field of microelectromechanical manufacturing, and particularly relates to a terahertz broadband combiner based on a gap waveguide. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] The terahertz frequency doubling technology is an important technical approach to realize terahertz sources and is also a research hotspot for terahertz sources internationally at present. However, at present, the output signal frequency range of terahertz frequency doubling source devices is limited to a single waveguide frequency band, and the working bandwidth is severely restricted, making it difficult to meet the growing broadband requirements of terahertz systems. To solve the above problems, frequency doubling devices in adjacent frequency bands need to be combined to achieve frequency band splicing and expand the working bandwidth; in addition, in a terahertz broadband system, the frequency bands are used intensively. To avoid waste of resources, there is also a need for combining terahertz signals in adjacent or spaced different frequency bands. Based on the above background conditions, a terahertz broadband combiner based on a gap waveguide is proposed.

[0004] Existing combiners are mainly divided into combiners with a microstrip structure, combiners with a dielectric structure, and combiners with a waveguide structure. However, the combiner with a microstrip structure has the advantages of easy processing, small volume, and wide frequency band, but as the working frequency increases, its loss is large and the power it can withstand is small; the combiner with a dielectric structure has low differential loss, good temperature characteristics, and a compact structure, but is severely restricted by processing technology and cost; for the existing combiner with a waveguide structure, it can withstand a large power and has good performance, but the working bandwidth is limited. Summary of the Invention

[0005] To overcome the deficiencies of the above-mentioned prior art, the present invention provides a terahertz broadband combiner based on a gap waveguide.

[0006] According to some embodiments, the present invention adopts the following technical solutions:

[0007] A terahertz broadband combiner based on a gap waveguide, comprising: a first standard waveguide port, a second standard waveguide port, a third combined port, three waveguide narrow-side height gradient matching transition structures, two input ridge waveguide gradient transition structures, a low-pass filtering structure, a combined gap waveguide structure, and a combined ridge waveguide gradient transition structure;

[0008] The first standard waveguide port is connected to the first ridge waveguide tapered transition structure through the first matching transition structure, and then connected to the low-pass filtering structure; the end of the low-pass filtering structure is connected to the combined gap waveguide structure, the end of the combined gap waveguide structure is connected to the combined ridge waveguide tapered transition structure, and the end of the combined ridge waveguide tapered transition structure is connected to the third combined port for outputting terahertz signals through the third matching transition structure;

[0009] The second standard waveguide port is connected to the second ridge waveguide tapered transition structure through the second matching transition structure, and the end of the second ridge waveguide tapered transition structure is connected to the input end of the combined gap waveguide structure.

[0010] Furthermore, absorbers are symmetrically arranged on both sides of the first ridge waveguide tapered transition structure and the combined ridge waveguide tapered transition structure.

[0011] Furthermore, the absorber structure is a rectangular cube structure, which is used to suppress the generation of parasitic modes.

[0012] Furthermore, the low-pass filtering structure is a high-low impedance low-pass filtering structure based on a gap waveguide.

[0013] Furthermore, the first matching transition structure, the first ridge waveguide tapered transition structure, the low-pass filtering structure, the combined gap waveguide structure, the combined ridge waveguide tapered transition structure, and the third matching transition structure are coaxially arranged.

[0014] Furthermore, the second matching transition structure and the second ridge waveguide tapered transition structure are coaxially arranged.

[0015] Furthermore, the first matching transition structure, the second matching transition structure, and the third matching transition structure are all gradually transitioned based on the narrow-side height of the standard rectangular waveguide.

[0016] Furthermore, the second matching transition structure also serves as a high-pass filter to achieve the function of blocking high-frequency signals while allowing low-frequency signals to pass through.

[0017] Furthermore, the transition forms between the standard rectangular waveguide port and the gap waveguide port respectively adopt a transition form based on the gradual change of the narrow-side height of the rectangular waveguide and a transition method based on the ridge waveguide taper.

[0018] Furthermore, the first standard waveguide port is used to input terahertz low-frequency signals, the second standard waveguide port is used to input terahertz high-frequency signals, and the third combined port is used to output terahertz combined signals.

[0019] The above technical solutions have the following beneficial effects:

[0020] (1) The present invention utilizes a slot waveguide as the overall transmission structure of a terahertz broadband combiner. A high-low impedance filtering structure with low-pass characteristics is designed based on the slot waveguide. At the same time, a rectangular waveguide structure is used as the high-pass filtering structure. The above two parts are respectively used as the transmission structures for terahertz low-frequency signals and high-frequency signals. For the combined terahertz signal, a slot waveguide with broadband transmission characteristics is used as the transmission structure. The combiner provided by the present invention has the advantages of a wide operating frequency band, low loss, and easy processing, and can effectively meet the requirements of terahertz system combining.

[0021] (2) The present invention designs a filtering structure based on the slot waveguide. In the embodiment, a high-low impedance filtering structure is adopted, but it is not limited to this structure, including other slot waveguide-based filtering structures such as bandgap filtering structures.

[0022] (3) The present invention uses a rectangular waveguide structure as the high-pass filtering structure in the terahertz combiner to achieve the function of blocking high-frequency signals and passing low-frequency signals.

[0023] (4) In order to facilitate testing and connection with standard waveguide devices, the present invention realizes the transition and conversion between the slot waveguide and the standard rectangular waveguide through a combination of a gradual height change matching transition based on the narrow side of the rectangular waveguide and a gradual transition based on the ridge waveguide.

[0024] (5) In order to suppress the generation of parasitic modes, the present invention adds a rectangular cubic absorber to avoid the appearance of resonance peaks within the operating frequency band.

[0025] The advantages of the additional aspects of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The specification drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0027] Figure 1 It is a schematic structural diagram of a terahertz broadband combiner based on a slot waveguide for Embodiment 1.

[0028] Figure 2 It is a graph of the S-parameter simulation results for Embodiment 1.

[0029] In the figure, 1, the first matching transition structure based on the gradual change of the narrow side height of the waveguide; 2, the first ridge waveguide gradual transition structure; 3, the low-pass filtering structure; 4, the combined slot waveguide structure; 5, the combined ridge waveguide gradual transition structure; 6, the third matching transition structure based on the gradual change of the narrow side height of the waveguide; 7, the second matching transition structure based on the gradual change of the narrow side height of the waveguide; 8, the second ridge waveguide gradual transition structure; 9, the absorber. Detailed implementation manners

[0030] The present disclosure will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further descriptions of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0032] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary implementation manners according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Embodiment 1

[0034] The object of the present invention is to solve the technical problems of narrow working frequency range, high processing difficulty, and large transmission loss of a terahertz combiner, and to provide a high-performance terahertz broadband combiner based on a gap waveguide to meet the broadband transmission requirements needed for the development of terahertz systems.

[0035] As Figure 1 shown, a terahertz broadband combiner based on a gap waveguide includes: a first standard waveguide port for inputting a terahertz low-frequency signal, a second standard waveguide port for inputting a terahertz high-frequency signal, a third combiner port for outputting a terahertz combined signal, three waveguide narrow-side height gradual matching transition structures, two input ridge waveguide gradual transition structures, a low-pass filter structure 3, a combined gap waveguide structure 4, and a combined ridge waveguide gradual transition structure 5;

[0036] The first standard waveguide port is connected to the first input ridge waveguide gradual transition structure 2 through the first matching transition structure 1, and then connected to the low-pass filter structure 3; the end of the low-pass filter structure is connected to the combined gap waveguide structure 4, the end of the combined gap waveguide structure 4 is connected to the combined ridge waveguide gradual transition structure 5, and the end of the combined ridge waveguide gradual transition structure 5 is connected to the third combiner port for outputting a terahertz signal through the third matching transition structure 6;

[0037] The second standard waveguide port is connected to the second ridge waveguide gradual transition structure 8 through the second matching transition structure 7, and the end of the second ridge waveguide gradual transition structure is connected to the input end of the combined gap waveguide structure 4;

[0038] Absorbers 9 are symmetrically arranged on both sides of the first ridge waveguide tapered transition structure and the combined ridge waveguide tapered transition structure. The structure of the absorber 9 is a rectangular cube structure, which is used to suppress the generation of parasitic modes.

[0039] The low-pass filter structure 3 is a high-low impedance low-pass filter structure or a bandgap filter structure based on a gap waveguide.

[0040] The first matching transition structure 1, the first ridge waveguide tapered transition structure 2, the low-pass filter structure 3, the combined gap waveguide structure 4, the combined ridge waveguide tapered transition structure 5 and the third matching transition structure 6 are coaxially arranged; the second matching transition structure 7 and the second ridge waveguide tapered transition structure 8 are coaxially arranged. The first matching transition structure 1, the second matching transition structure 7 and the third matching transition structure 6 are all gradually transitioned based on the narrow side height of the standard rectangular waveguide.

[0041] The transition form between the standard rectangular waveguide port and the gap waveguide port simultaneously adopts a transition form based on the gradual change of the narrow side height of the rectangular waveguide and a transition method based on the ridge waveguide, which is used to achieve broadband mode conversion and impedance matching.

[0042] The terahertz low-frequency signal is input from the first standard waveguide port and is transmitted through the first matching transition structure 1 and the first ridge waveguide tapered transition structure 2 to the high-low impedance low-pass filter structure 3 based on the gap waveguide. At this time, the working mode of the terahertz low-frequency signal is gradually converted from the TE10 mode to the quasi-TEM mode. Then, the terahertz low-frequency signal continues to be transmitted in the direction of the combined port along the combined gap waveguide structure 4 through the combined ridge waveguide tapered transition structure 5. The cube structures on both sides of the low-pass filter structure 3 and the combined gap waveguide structure 4 are part of the gap waveguide, which mainly suppresses the electromagnetic wave from outputting to both sides.

[0043] The terahertz high-frequency signal is converged to the combined gap waveguide structure 4 through the second matching transition structure 7 and the second ridge waveguide tapered transition structure 8 from the second waveguide port, and also continues to be transmitted in the direction of the third combined port along the combined gap waveguide structure 4 through the combined ridge waveguide tapered transition structure 5.

[0044] The terahertz low-frequency signal input from the first waveguide port is transmitted to the combined gap waveguide structure 4. Since the second matching transition structure is gradually formed based on the narrow side height of the standard rectangular waveguide, it has the same high-pass filter characteristic as the standard rectangular waveguide structure, which will suppress the terahertz low-frequency signal from being output from the second waveguide port. Therefore, the terahertz low-frequency signal input from the first waveguide port will be output from the third combined port through the combined transmission structure.

[0045] Similarly, the terahertz high-frequency signal input from the second waveguide port is transmitted to the multiplexing gap waveguide structure 4. Since the high-low impedance low-pass filtering structure 3 based on the gap waveguide has low-pass filtering characteristics, it will suppress the output of the terahertz high-frequency signal to the first waveguide port. Therefore, the terahertz high-frequency signal input from the second waveguide port will also be output from the third multiplexing port by the multiplexing transmission structure.

[0046] As Figure 2 shown, in this embodiment, a terahertz broadband multiplexer based on the gap waveguide for two waveguide bands of 0.11 THz - 0.17 THz and 0.22 THz - 0.26 THz is designed. It can be seen from the simulation results that S31 is about -1 dB in the range of 0.11 THz - 0.17 THz and S32 is about -1 dB in the range of 0.22 THz - 0.26 THz, indicating good transmission characteristics from port 1 to port 3 and from port 2 to port 3. At the same time, both S21 and S12 are less than -10 dB, indicating good isolation between port 1 and port 2.

[0047] The present invention proposes a design of a terahertz broadband multiplexer based on the gap waveguide. By utilizing the low-pass filtering characteristics of the high-low impedance transformation structure and the high-pass filtering characteristics of the rectangular waveguide based on the gap waveguide transmission structure, a broadband terahertz multiplexer design is realized. Compared with the prior art, it can effectively expand the working bandwidth of the terahertz multiplexer. At the same time, since the structure is designed based on the gap waveguide transmission structure, it can be processed in an open field, reducing the process difficulty. In addition, due to the structural characteristics of the gap waveguide itself, the assembly requirements are reduced. Meanwhile, the gap waveguide has good high-frequency transmission characteristics. Using the gap waveguide structure for the design of the multiplexing device can effectively reduce the transmission loss of the device.

[0048] Although the specific implementation manners of the present invention have been described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications or deformations that can be made without creative labor on the basis of the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A terahertz broadband combiner based on a gap waveguide, characterized in that, Including: A first standard waveguide port, a second standard waveguide port, a third combining port, three waveguide narrow-side height gradient matching transition structures, two input ridge waveguide gradient transition structures, a low-pass filtering structure, a combining gap waveguide structure, and a combining ridge waveguide gradient transition structure; The first standard waveguide port is connected to the first ridge waveguide gradient transition structure (2) through the first matching transition structure (1), and then connected to the low-pass filtering structure (3); the end of the low-pass filtering structure (3) is connected to the combining gap waveguide structure (4), the end of the combining gap waveguide structure (4) is connected to the combining ridge waveguide gradient transition structure (5), and the end of the combining ridge waveguide gradient transition structure (5) is connected to the third combining port for outputting terahertz signals through the third matching transition structure (6); The second standard waveguide port is connected to the second ridge waveguide gradient transition structure (8) through the second matching transition structure (7), and the end of the second ridge waveguide gradient transition structure (8) is connected to the input end of the combining gap waveguide structure (4); The second matching transition structure (7) simultaneously serves as a high-pass filter to achieve the function of blocking low-frequency signals for high-frequency signal input.

2. The terahertz broadband combiner based on a gap waveguide according to claim 1, wherein Absorbers are symmetrically arranged on both sides of the first ridge waveguide gradient transition structure (2) and the combining ridge waveguide gradient transition structure (5).

3. The terahertz broadband combiner based on a gap waveguide according to claim 2, characterized in that, The absorber (9) structure is a rectangular cube structure for suppressing the generation of parasitic modes.

4. A terahertz broadband combiner based on a gap waveguide according to claim 1, characterized in that, The low-pass filtering structure (3) is a high-low impedance low-pass filtering structure based on a gap waveguide.

5. A terahertz broadband combiner based on a gap waveguide according to claim 1, wherein, The first matching transition structure (1), the first ridge waveguide gradient transition structure (2), the low-pass filtering structure (3), the combining gap waveguide structure (4), the combining ridge waveguide gradient transition structure (5), and the third matching transition structure (6) are coaxially arranged.

6. The broadband terahertz combiner based on a gap waveguide according to claim 1, wherein The second matching transition structure (7) and the second ridge waveguide gradient transition structure (8) are coaxially arranged.

7. A terahertz broadband combiner based on a gap waveguide according to claim 1, characterized in that The first matching transition structure (1), the second matching transition structure (7), and the third matching transition structure (6) are all formed by gradually transitioning based on the narrow-side height of a standard rectangular waveguide.

8. A terahertz broadband combiner based on a gap waveguide according to claim 1, characterized in that The transition forms between the standard rectangular waveguide port and the gap waveguide port respectively adopt a transition form based on the narrow-side height gradient of the rectangular waveguide and a transition method based on the ridge waveguide gradient.

9. The terahertz broadband combiner based on a gap waveguide according to claim 1, characterized in that, The first standard waveguide port is used to input terahertz low-frequency signals, the second standard waveguide port is used to input terahertz high-frequency signals, and the third combining port is used to output terahertz combined signals.

Images