CN213936481U

CN213936481U - Waveguide filter

Info

Publication number: CN213936481U
Application number: CN202121606939.4U
Authority: CN
Inventors: 吴炼; 刘畅; 金曙晨; 王明
Original assignee: Chengdu Weibin Technology Co Ltd
Current assignee: Chengdu Weibin Technology Co Ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2021-08-10
Anticipated expiration: 2031-07-15

Abstract

The application provides a waveguide filter, including forming in the air waveguide chamber of metalwork, the air waveguide intracavity is equipped with a plurality of baffles along the length direction interval, and the baffle surface is on a parallel with air waveguide chamber top surface and bottom surface, and the baffle upper surface has first predetermined interval with air waveguide chamber top surface, and the baffle lower surface has the second with air waveguide chamber bottom surface and predetermines the interval, and the baffle both sides are connected with air waveguide chamber lateral wall. The metal piece comprises a pair of metal plates which are symmetrically arranged and an intermediate plate which is clamped between the metal plates, a groove is formed in one surface, in contact with the intermediate plate, of each metal plate, the intermediate plate comprises a pair of plate bodies, the interval between the pair of plate bodies is matched with the groove, the air waveguide cavity is formed by the grooves of the pair of metal plates and the interval between the pair of plate bodies, and the partition plate is arranged at the interval. The partition plates arranged at intervals are introduced into the air cavity through the assembly type, a plurality of resonant stages are formed to realize microwave filtering, and the input end and the output end of the resonant stages are waveguide ports and are directly connected into waveguide transmission lines to meet the filtering requirement.

Description

Waveguide filter

Technical Field

The utility model relates to a radio frequency microwave technique especially relates to a waveguide filter.

Background

At present, filters used in the microwave industry can be classified into microstrip filters, LC filters, dielectric filters, cavity filters, and the like. In many radar application environments, the antenna is generally a horn antenna, signals are received by the antenna and then transmitted through a waveguide, and if the received signals need to be filtered and frequency-selected, the conventional method is to convert the waveguide transmission mode into microstrip transmission or coaxial transmission and then add a filter. This results in a considerable increase in costs and an increase in the required installation space; and the design of the whole radar is greatly hindered.

SUMMERY OF THE UTILITY MODEL

Not enough to above-mentioned relevant prior art, the utility model provides a waveguide filter realizes introducing the baffle that the interval set up in the air chamber through the assembled, forms a plurality of resonance levels and realizes microwave filtering, and its input-output end is the waveguide mouth, directly connects and can reach the filtering requirement in the waveguide transmission line.

In order to realize the purpose of the utility model, the following scheme is proposed:

the waveguide filter is characterized by comprising an air waveguide cavity formed in a metal piece, wherein a plurality of partition plates are arranged in the air waveguide cavity at intervals along the length direction, the surfaces of the partition plates are parallel to the top surface and the bottom surface of the air waveguide cavity, a first preset interval is formed between the upper surface of each partition plate and the top surface of the air waveguide cavity, a second preset interval is formed between the lower surface of each partition plate and the bottom surface of the air waveguide cavity, and the two sides of each partition plate are connected with the side wall of the air waveguide cavity.

The metal piece comprises a pair of metal plates and an intermediate plate, the metal plates are symmetrically arranged, the intermediate plate is clamped between the metal plates, one surfaces of the metal plates, which are in contact with the intermediate plate, are provided with grooves, the intermediate plate comprises a pair of plate bodies, the interval between the pair of plate bodies is matched with the grooves, the grooves of the pair of metal plates and the interval between the pair of plate bodies form the air waveguide cavity, and the partition plate is arranged at the interval.

Furthermore, the thickness of the partition board is consistent with that of the middle board, and the partition board and the middle board are integrally processed and molded.

Further, be equipped with a plurality of first pilot holes on the metal sheet, be equipped with a plurality of second pilot holes on the intermediate lamella, the second pilot hole matches with first pilot hole, in order to be connected a pair of metal sheet and intermediate lamella as an organic whole in first pilot hole and second pilot hole through wearing to establish the fastener.

Furthermore, the two ends of the metal plate in the length direction extend to two sides to form protruding parts, and mounting holes are formed in the protruding parts and used for mounting the waveguide filter in an application place.

Furthermore, two ends of the air waveguide cavity are provided with waveguide ports.

The beneficial effects of the utility model reside in that:

the microwave filter is realized by introducing partition boards arranged at intervals into an air cavity through assembling a pair of metal pieces and a middle board, a plurality of resonant stages are formed to realize microwave filtering, the input and output ends of the microwave filter are waveguide ports and are directly connected into a waveguide transmission line to meet the filtering requirement, when the working frequency is 35.4GHz +/-250 MHz, the input and output standing wave is less than or equal to 2, the insertion loss is less than or equal to 3dB, the out-of-band rejection ratio is that the rejection is more than or equal to 30dBc for 30 GHz-34.4 GHz, and the rejection is more than or equal to 30dBc for 36.4 GHz-40 GHz.

Drawings

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

Fig. 1 is a perspective view showing the overall structure of a waveguide filter according to an embodiment of the present application.

Fig. 2 is a perspective view showing the overall structure of the waveguide filter according to the embodiment of the present application.

Fig. 3 shows a schematic exploded structure diagram of a waveguide filter according to an embodiment of the present application.

Fig. 4 shows a cross-sectional view of the interior of a waveguide filter according to an embodiment of the present application.

Fig. 5 shows a simulation curve of a standing wave of a waveguide filter according to an embodiment of the present application.

Fig. 6 shows waveguide filter loss and suppression simulation curves of an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings, but the described embodiments of the present invention are some embodiments of the present invention, not all embodiments.

The embodiment of the application provides a waveguide filter, and the design idea is as follows:

by dividing the entire air cavity of the waveguide into a plurality of small air cavities; each air cavity can be equivalent to an inductor parallel capacitor, so that a plurality of resonant stages are formed, and microwave filtering function can be realized by cascading a plurality of resonant stages as long as the volumes and the number of the air cavities are simulated.

In order to overcome the problem of difficulty in production and processing, the waveguide filter is divided into three parts, and each part is subjected to a design mode of independent high-precision processing and reassembly. The waveguide is divided into two parts from the center, then a metal sheet with a plurality of holes in the middle is designed, the size of each hole of the metal sheet is subjected to three-dimensional simulation through electromagnetic simulation software, and then the three parts are fixedly installed through screws.

Specifically, as shown in fig. 1 to 4, the waveguide filter of the present embodiment includes an air waveguide cavity 3 formed in a metal member, a plurality of partition plates 21 are disposed at intervals in the air waveguide cavity 3 along a length direction, surfaces of the partition plates 21 are parallel to a top surface and a bottom surface of the air waveguide cavity 3, an upper surface of each partition plate 21 and the top surface of the air waveguide cavity 3 have a first preset distance, a lower surface of each partition plate 21 and the bottom surface of the air waveguide cavity 3 have a second preset distance, and two sides of each partition plate 21 are connected to sidewalls of the air waveguide cavity 3. Two ends of the air waveguide cavity 3 are waveguide ports. The partition 21 is a thin partition.

Specifically, the metal part in this example includes a pair of metal plates 1 symmetrically arranged and an intermediate plate 2 sandwiched between the metal plates 1, a groove 11 is formed in a surface of the metal plate 1 contacting the intermediate plate 2, the intermediate plate 2 includes a pair of plate bodies, a gap 20 between the pair of plate bodies matches the groove 11, the groove 11 of the pair of metal plates 1 and the gap 20 between the pair of plate bodies form the air waveguide cavity 3, and a partition plate 21 is disposed at the gap 20, wherein the thickness of the partition plate 21 is the same as that of the intermediate plate 2, and the partition plate 21 is integrally formed with the intermediate plate 2. The intermediate plate 2 is also made of the same metal material as the metal plate 1.

Be equipped with a plurality of first pilot holes 12 on the metal sheet 1, be equipped with a plurality of second pilot holes 22 on the intermediate lamella 2, second pilot hole 22 matches with first pilot hole 12, during the assembly, arranges intermediate lamella 2 in between the metal sheet 1, counterpoints the back, is in order to connect as an organic whole a pair of metal sheet 1 and intermediate lamella 2 in first pilot hole 12 and second pilot hole 22 through wearing to establish the fastener.

Protruding portions 14 are formed by extending two ends of the metal plate 1 in the length direction to two sides, and mounting holes 13 are formed in the protruding portions 14 and used for mounting the waveguide filter in an application place.

Simulation verification:

a waveguide filter of a 35.4GHz frequency band is selected for simulation design, and the waveguide filter has the following index requirements: the working frequency is as follows: 35.4GHz +/-250 MHz; input and output standing waves: less than or equal to 2; insertion loss: less than or equal to 3 dB; the out-of-band inhibition ratio is that the inhibition on 30 GHz-34.4 GHz is more than or equal to 30dBc, and the inhibition on 36.4 GHz-40 GHz is more than or equal to 30 dBc.

As shown in fig. 5, a simulation curve of the standing wave of the waveguide filter, where m1 and m2 points represent bandwidths, m1 point corresponds to the lower limit of the bandwidth, m2 point corresponds to the upper limit of the bandwidth, and m3 point is the center frequency of the bandwidth, corresponding to the operating frequency: 35.4GHz +/-250 MHz, and it can be seen that in the frequency band, the return loss is below-15.7467, and the return loss is converted into standing wave which is about 1.4 and less than 2, and meets the index requirement.

As shown in fig. 6, which is a simulation curve of waveguide filter loss and suppression, points m1 and m2 in the graph represent bandwidths, a point m1 corresponds to the lower limit of the bandwidth, a point m2 corresponds to the upper limit of the bandwidth, and a point m3 is the center frequency of the bandwidth, corresponding to the operating frequency: 35.4GHz +/-250 MHz, and m4 and m 5 respectively represent the left and right double-sideband suppression ratios, so that the insertion loss is close to 0 in the frequency band and is consistent with less than or equal to 3dB, and the out-of-band suppression ratios are that the suppression on 30 GHz-34.4 GHz is more than or equal to 30dBc, and the suppression on 36.4 GHz-40 GHz is more than or equal to 30 dBc.

The waveguide filter of this example meets the set 35.4GHz filter specification requirement.

The foregoing is merely a preferred embodiment of the invention and is not intended to be exhaustive or to limit the invention. It should be understood by those skilled in the art that various changes and equivalent substitutions made herein may be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. The waveguide filter is characterized by comprising an air waveguide cavity (3) formed in a metal piece, wherein a plurality of partition plates (21) are arranged in the air waveguide cavity (3) at intervals along the length direction, the surfaces of the partition plates (21) are parallel to the top surface and the bottom surface of the air waveguide cavity (3), the upper surface of each partition plate (21) and the top surface of the air waveguide cavity (3) are provided with a first preset interval, the lower surface of each partition plate (21) and the bottom surface of the air waveguide cavity (3) are provided with a second preset interval, and two sides of each partition plate (21) are connected with the side wall of the air waveguide cavity (3).

2. The waveguide filter according to claim 1, wherein the metal member comprises a pair of metal plates (1) symmetrically arranged and an intermediate plate (2) sandwiched between the metal plates (1), a groove (11) is formed in a surface of the metal plate (1) contacting the intermediate plate (2), the intermediate plate (2) comprises a pair of plate bodies, a space (20) between the pair of plate bodies is matched with the groove (11), the groove (11) of the pair of metal plates (1) and the space (20) of the pair of plate bodies form the air waveguide cavity (3), and the partition plate (21) is arranged at the space (20).

3. A waveguide filter according to claim 2, characterized in that the thickness of the partition (21) corresponds to the thickness of the intermediate plate (2).

4. A waveguide filter according to claim 3, characterized in that the partition (21) is integrally formed with the intermediate plate (2).

5. The waveguide filter according to claim 2, wherein the metal plate (1) is provided with a plurality of first assembling holes (12), the intermediate plate (2) is provided with a plurality of second assembling holes (22), the second assembling holes (22) are matched with the first assembling holes (12), and a pair of metal plates (1) and the intermediate plate (2) are connected into a whole by penetrating fasteners into the first assembling holes (12) and the second assembling holes (22).

6. The waveguide filter according to claim 2, wherein the metal plate (1) has projections (14) formed at both ends in the longitudinal direction thereof so as to extend to both sides, and the projections (14) are provided with mounting holes (13) for mounting the waveguide filter in an application place.

7. A waveguide filter according to claim 1, characterized in that the air waveguide cavity (3) is terminated by a waveguide port.