Terahertz waveguide cavity filter

Abstract

The utility model relates to the technical field of terahertz communication, in particular to a terahertz waveguide cavity filter, which solves the problem of high waveguide processing difficulty in the prior art. Comprising an upper metal shell and a lower metal shell which are connected with each other, an upper through groove is formed in the upper metal shell, a lower through groove is formed in the lower metal shell, the upper through groove and the lower through groove are oppositely arranged to form a rectangular waveguide, and a metal diaphragm is arranged in the rectangular waveguide; and a positioning assembly is arranged between the upper metal shell and the lower metal shell. The filter has the beneficial effects that an equivalent filter circuit is formed in a rectangular waveguide cavity by adopting a metal diaphragm in the filter, so that a filter resonance circuit is realized; the rectangular waveguide is coherent, regular in structure and low in processing difficulty; the positioning assembly ensures that the relative position of the upper metal shell and the lower metal shell is accurate when the upper metal shell and the lower metal shell are connected, thereby ensuring that the upper through groove and the lower through groove are accurately aligned, ensuring that the structure of the rectangular waveguide is complete, and facilitating the assembly of the filter.

Description

Technical Field

[0001] This utility model relates to the field of terahertz communication technology, and in particular to a terahertz waveguide cavity filter. Background Technology

[0002] With the booming development of emerging business areas such as 5G mobile internet and the Internet of Things, future communication systems are placing increasingly higher demands on channel transmission capacity, data transmission rate, and bit error rate. Terahertz communication, with its higher carrier frequency, has become the preferred technology for future sixth-generation (6G) communication due to its high transmission rate, high throughput, low latency, and strong anti-interference capability and security. Among them, terahertz filters, as one of the important functional components, can selectively allow electromagnetic waves of specific frequency bands to pass through or filter out interference signals mixed in the useful electromagnetic spectrum. They are an indispensable transmission component in terahertz systems, and their performance often affects the quality of the entire system. However, in the terahertz band, the small physical size has become an important factor limiting the development of high-performance filters. Terahertz waveguide cavity filters based on standard rectangular waveguides have a regular structure, mature technology, and are relatively easy to manufacture; their closed structure can also avoid electromagnetic radiation and support high-power electromagnetic energy transmission, making them one of the important development directions of terahertz filter technology.

[0003] The prior art patent with publication number CN209088040U discloses a terahertz quasi-elliptic waveguide filter that is easy to implement with CNC. It includes an upper structural block and a lower structural block, which are detachably connected. An H-plane single-sided slot waveguide structure is provided between the upper and lower structural blocks. The H-plane single-sided slot waveguide structure includes a source input waveguide, a load output waveguide, and four resonant cavities with the same structural size. The four resonant cavities are arranged in a folded arrangement along the H-plane. Adjacent resonant cavities are magnetically coupled, and non-adjacent resonant cavities are cross-electrically coupled.

[0004] The four resonant cavities of the aforementioned filter are arranged in a folded pattern along the H-plane, which makes the waveguide fabrication on the structural block difficult and requires high-level technology. Utility Model Content

[0005] This invention proposes a terahertz waveguide cavity filter, which solves the problem of high difficulty in waveguide fabrication in the prior art.

[0006] The technical solution of this utility model is implemented as follows:

[0007] A terahertz waveguide cavity filter includes an upper metal shell and a lower metal shell connected to each other. The upper metal shell has an upper through slot, and the lower metal shell has a lower through slot. The upper and lower through slots are arranged opposite each other to form a rectangular waveguide, and a metal diaphragm is disposed within the rectangular waveguide. A positioning component is disposed between the upper and lower metal shells. Fabricating the rectangular waveguide into upper and lower through slots facilitates the installation of the metal diaphragm within the rectangular waveguide. Furthermore, since both the upper and lower through slots are straight slots, they can be fabricated using traditional machining processes, reducing fabrication difficulty. Additionally, the positioning component ensures accurate relative positioning of the upper and lower metal shells when they are connected, thereby ensuring accurate alignment of the upper and lower through slots and facilitating filter assembly.

[0008] The rectangular waveguide has multiple symmetrically arranged metal diaphragms on its narrow side, and the cavity between two adjacent sets of metal diaphragms is a resonant cavity. The metal diaphragms are parallel to the E-plane of the waveguide, and through holes are formed between two symmetrically arranged metal diaphragms. At this time, a series of resonant cavities with alternating diaphragm-waveguide cavities are formed between two adjacent sets of metal diaphragms, where the diaphragms act as coupling agents, which can be equivalent to a T-type circuit. The adjacent resonant cavities without diaphragms are coupled together to form an E-plane waveguide filter.

[0009] The depths of both the upper and lower through slots are greater than or equal to the width of the metal diaphragm. This ensures that the metal diaphragm will not protrude from the lower metal housing or its contact surface after being installed into the lower or upper through slot, thus facilitating the subsequent connection between the upper and lower metal housings.

[0010] The positioning component includes guide pins and guide holes. Guide holes are provided on both the upper and lower metal housings, with the guide holes on the upper and lower metal housings arranged opposite each other. The guide pins engage with the guide holes. The engagement of the guide pins and guide holes ensures accurate relative positioning of the upper and lower metal housings after connection, thereby ensuring accurate alignment of the upper and lower through slots and maintaining the structural integrity of the rectangular waveguide.

[0011] The surfaces of the upper and lower metal housings are coated with a silver plating layer. The silver plating layer is 10 μm thick and can effectively reduce metal loss caused by the high-frequency skin effect to achieve low insertion loss and meet the wide operating temperature requirements from -20℃ to 60℃.

[0012] The upper and lower metal housings are connected by screws. The upper metal housing has a threaded connection hole, and the lower metal housing has a through hole. The screws pass through the through holes and connect to the threaded connection holes. After the upper and lower metal housings are mated, they are fixed together by screws to ensure a stable connection between the upper and lower metal housings, thereby ensuring the structural stability of the filter.

[0013] The upper metal housing has multiple threaded connection holes symmetrically arranged on both sides of the upper through slot, and the lower metal housing has multiple through holes symmetrically arranged on both sides of the lower through slot. The symmetrical arrangement of the through holes and threaded connection holes ensures that screws are installed on both sides of the rectangular waveguide, guaranteeing a tight fit between the upper and lower through slots.

[0014] The upper and lower metal housings are provided with locating pins and locating holes on their end faces. The locating pins and locating holes ensure that the ports of the rectangular waveguide are accurately connected to the test equipment or other terahertz components.

[0015] The upper and lower metal housings are provided with flange threaded holes on their end faces. The filter is connected to the test equipment or other terahertz components via connecting bolts in the flange threaded holes.

[0016] Both the upper and lower metal housings are provided with rectangular recesses, with through holes or threaded connection holes located at the bottom of the rectangular recesses; flange threaded holes are located on the sidewalls of the rectangular recesses. After the upper and lower metal housings are connected, the heads and ends of the screws are located within the rectangular recesses; similarly, after the filter is installed, the heads of the connecting bolts are also located within the rectangular recesses. The sidewalls of the rectangular recesses provide protection for the screws and connecting bolts.

[0017] The beneficial effects of this utility model are: 1. The filter uses a metal diaphragm to form an equivalent filter circuit in the rectangular waveguide cavity to realize the filter resonant circuit; the rectangular waveguide is continuous and the structure is regular, and the upper and lower through slots are both straight slots, which can be completed using traditional machining processes, and the processing difficulty is low.

[0018] 2. The positioning component ensures that the upper and lower metal housings are accurately positioned relative to each other when connected, thereby ensuring accurate alignment of the upper and lower through slots, maintaining the structural integrity of the rectangular waveguide, and facilitating filter assembly.

[0019] 3. A silver plating layer is applied to the surfaces of the upper and lower metal housings. The silver plating layer can effectively reduce the metal loss caused by the high-frequency skin effect to achieve lower insertion loss and meet the wide operating temperature requirements from -20℃ to 60℃.

[0020] 4. Rectangular recesses are provided on the upper and lower metal housings. The screws used to connect the upper and lower metal housings are placed inside the rectangular recesses. The bolt heads used to install the filter are located inside the rectangular recesses. The sidewalls of the rectangular recesses can protect the screws and connecting bolts. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of a terahertz waveguide cavity filter structure according to the present invention;

[0023] Figure 2 This is a schematic diagram of the upper metal shell structure;

[0024] Figure 3 A cross-section of the filter Figure 1 ;

[0025] Figure 4 A cross-section of the filter Figure 2 ;

[0026] Figure 5 This is a schematic diagram of a metal diaphragm installed inside a rectangular waveguide.

[0027] In the diagram: 1. Upper metal housing, 2. Screw, 3. Flat washer, 4. Spring washer, 5. Locating pin, 6. Lower metal housing, 7. Guide pin, 8. Rectangular waveguide, 81. Narrow side, 82. Resonant cavity, 9. Metal diaphragm, 10. Flange threaded hole. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example 1, as Figure 1As shown, a terahertz waveguide cavity filter includes an upper metal housing 1 and a lower metal housing 6 connected to each other. The upper metal housing 1 has an upper through slot, and the lower metal housing 6 has a lower through slot. The upper and lower through slots are arranged opposite each other to form a rectangular waveguide 8, and a metal diaphragm 9 is disposed inside the rectangular waveguide 8. A positioning component is provided between the upper metal housing 1 and the lower metal housing 6. The metal diaphragm 9 is used inside the filter to form an equivalent filter circuit in the rectangular waveguide 8 to realize a filter resonant circuit. The rectangular waveguide 8 is continuous and has a regular structure. Both the upper and lower through slots are straight slots, which can be completed using traditional machining processes, making the processing difficult. In addition, the positioning component ensures that the upper metal housing 1 and the lower metal housing 6 are accurately positioned when connected, thereby ensuring accurate alignment of the upper and lower through slots, ensuring the structural integrity of the rectangular waveguide 8, and facilitating the assembly of the filter.

[0030] Furthermore, such as Figure 5 As shown, multiple sets of symmetrically arranged metal diaphragms 9 are provided on the narrow side 81 of the rectangular waveguide 8. The cavity of the rectangular waveguide 8 between two adjacent groups of metal diaphragms 9 is a resonant cavity 82. Specifically, the wide side dimension of the rectangular waveguide 8 is 1.092 mm, and the narrow side dimension 81 dimension of the rectangular waveguide 8 is 0.546 mm. The metal diaphragms 9 are perpendicular to the narrow side 81 of the rectangular waveguide 8 and form through holes between each group of metal diaphragms 9. The top spacing of two symmetrically arranged metal diaphragms 9 is the width of the through hole. The top spacing of the first and sixth groups of metal diaphragms 9 is 0.587 mm, the top spacing of the second and fifth groups of metal diaphragms 9 is 0.417 mm, and the top spacing of the third and fourth groups of metal diaphragms 9 is 0.379 mm. A series of resonant cavities with alternating diaphragm-waveguide cavities are formed between the rectangular waveguide 8 and the groups of metal diaphragms. The metal diaphragms 9 play a coupling role and can be equivalent to a T-type circuit. Thus, the E-plane waveguide filter is formed by coupling adjacent resonant cavities 82 without metal diaphragms 9.

[0031] In this embodiment, the rectangular waveguide 8 has six sets of metal diaphragms 9 inside its cavity, which divide the cavity into five resonant cavities 82. Specifically, the resonant cavities 82 include a first resonant cavity, a second resonant cavity, a third resonant cavity, a fourth resonant cavity, and a fifth resonant cavity arranged in sequence. A fifth-order 0.5dB ripple Chebyshev low-pass filter circuit is selected, and the normalized impedance values ​​of each component are determined. Then, a K-inverter is used to transform the original low-pass prototype circuit into a modified low-pass prototype circuit. Subsequently, the modified low-pass components are transformed into a band-pass filter series resonant circuit, and the corresponding normalized values ​​of the components are calculated. Finally, the actual values ​​of each circuit component are determined according to the frequency of the filter, thereby obtaining the final length of each resonant cavity and the size of the metal diaphragms. That is, the lengths of the first and fifth resonant cavities are 0.7779mm, the lengths of the second and fourth resonant cavities are 0.8303mm, and the length of the third resonant cavity is 0.8338mm; the thickness of the metal diaphragm 9 is 0.508mm.

[0032] Furthermore, the depths of both the upper and lower through slots are greater than or equal to the width of the metal diaphragm 9. This ensures that the metal diaphragm 9 will not protrude from the contact surface of the lower metal housing 1 or lower metal housing 6 after being installed into the lower or upper through slot, thus facilitating the subsequent connection between the upper metal housing 1 and the lower metal housing 6. In addition, the sum of the depth dimensions of the upper and lower through slots is equal to the width dimension of the rectangular waveguide 8, resulting in a large tolerance for depth errors and low processing difficulty during the fabrication of the upper or lower through slots.

[0033] Example 2, based on Example 1, provides a terahertz waveguide cavity filter, such as... Figure 2 , Figure 4 As shown, the positioning assembly includes a guide pin 7 and a guide hole. Both the upper metal housing 1 and the lower metal housing 6 are provided with guide holes. The guide holes on the upper metal housing 1 and the lower metal housing 6 are arranged opposite to each other, and the guide pin 7 engages with the guide hole. The engagement of the guide pin 7 with the guide hole ensures accurate relative positioning of the upper metal housing 1 and the lower metal housing 6 after connection, thereby ensuring accurate alignment of the upper and lower through slots and maintaining the structural integrity of the rectangular waveguide.

[0034] Furthermore, the surfaces of the upper metal housing 1 and the lower metal housing 6 are provided with a silver plating layer. The silver plating layer has a thickness of 10 μm. The silver plating layer can effectively reduce the metal loss caused by the high-frequency skin effect to achieve lower insertion loss and meet the wide operating temperature requirements from -20℃ to 60℃.

[0035] Example 3, based on Example 2, provides a terahertz waveguide cavity filter, such as... Figure 2 , Figure 3As shown, the upper metal housing 1 and the lower metal housing 6 are connected by screws 2. The upper metal housing 1 has a threaded connection hole, and the lower metal housing 6 has a through hole. The screws 2 pass through the through holes and connect with the threaded connection holes. After the upper metal housing 1 and the lower metal housing 6 are mated, they are fixed by the screws 2 to ensure a stable connection between the upper metal housing 1 and the lower metal housing 6, thereby ensuring the structural stability of the filter. Furthermore, before installing the screws 2, flat washers 3 and spring washers 4 are fitted onto the screws 2 to ensure the installation stability of the screws 2.

[0036] Furthermore, the upper metal housing 1 is provided with multiple threaded connection holes, which are symmetrically arranged on both sides of the upper through groove. The lower metal housing 6 is provided with multiple through holes, which are symmetrically arranged on both sides of the lower through groove. In this embodiment, two threaded connection holes are provided on each side of the upper through groove, and two through holes are provided on each side of the lower through groove. The symmetrical arrangement of the through holes and threaded connection holes ensures that the upper metal housing 1 and the lower metal housing 6 are evenly pressurized after the screw 2 is tightened, thus ensuring a tight fit between the upper and lower through grooves.

[0037] Furthermore, the end faces of the upper metal housing 1 and the lower metal housing 6 are provided with locating pins 5 and locating holes. The end faces of the upper metal housing 1 and the lower metal housing 6 are provided with flange threaded holes 10. The locating pins 5 and locating holes ensure the accurate relative position of the filter with the test equipment or other terahertz components; the flange threaded holes 10 are connected with connecting bolts, and the filter is connected to the test equipment or other terahertz components through the connecting bolts.

[0038] Furthermore, both the upper metal housing 1 and the lower metal housing 6 are provided with rectangular recesses, with through holes or threaded connection holes located at the bottom of the rectangular recesses; flange threaded holes 10 are located on the side walls of the rectangular recesses. After the filter is assembled, the head and end of the screw 2 are located within the rectangular recesses; at the same time, the head of the connecting bolt is also located within the rectangular recesses, and the rectangular recesses can protect the screw 2 and the connecting bolt.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A terahertz waveguide cavity filter comprising an upper metal housing (1) and a lower metal housing (6) connected to each other, characterized in that, The upper metal housing (1) is provided with an upper through slot, and the lower metal housing (6) is provided with a lower through slot. The upper through slot and the lower through slot are arranged opposite to each other to form a rectangular waveguide (8). A metal diaphragm (9) is provided inside the rectangular waveguide (8). A positioning component is provided between the upper metal housing (1) and the lower metal housing (6).

2. The terahertz waveguide cavity filter of claim 1, wherein, Multiple sets of symmetrically arranged metal films (9) are provided on the narrow side (81) of the rectangular waveguide (8).

3. The terahertz waveguide cavity filter of claim 2, wherein, The depths of both the upper and lower through slots are greater than or equal to the width of the metal diaphragm (9).

4. The terahertz waveguide cavity filter according to any one of claims 1 to 3, characterized in that, The positioning component includes a guide pin (7) and a guide hole. Both the upper metal housing (1) and the lower metal housing (6) are provided with guide holes. The guide holes on the upper metal housing (1) and the guide holes on the lower metal housing (6) are arranged opposite to each other. The guide pin (7) cooperates with the guide hole.

5. The terahertz waveguide cavity filter of claim 4, wherein, The surfaces of the upper metal casing (1) and the lower metal casing (6) are provided with a silver plating layer.

6. The terahertz waveguide cavity filter according to any one of claims 1 to 3, 5, wherein The upper metal housing (1) and the lower metal housing (6) are connected by screws (2). The upper metal housing (1) is provided with a threaded connection hole, and the lower metal housing (6) is provided with a through hole. The screws (2) pass through the through hole and connect with the threaded connection hole.

7. The terahertz waveguide cavity filter of claim 6, wherein, The upper metal housing (1) is provided with multiple threaded connection holes, which are symmetrically arranged on both sides of the upper through groove. The lower metal housing (6) is provided with multiple through holes, which are symmetrically arranged on both sides of the lower through groove.

8. The terahertz waveguide cavity filter of claim 7, wherein, The end faces of the upper metal shell (1) and the lower metal shell (6) are provided with positioning pins (5) and positioning holes.

9. The terahertz waveguide cavity filter according to claim 7 or 8, characterized in that, Flange threaded holes (10) are provided on the end faces of the upper metal shell (1) and the lower metal shell (6).

10. The terahertz waveguide cavity filter according to claim 9, characterized in that, Both the upper metal shell (1) and the lower metal shell (6) are provided with rectangular grooves, and through holes or threaded connection holes are provided at the bottom of the rectangular grooves; flange threaded holes (10) are provided on the side wall of the rectangular grooves.

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