CN219575909U

CN219575909U - Q frequency band broadband quadrature mode coupler

Info

Publication number: CN219575909U
Application number: CN202320569650.2U
Authority: CN
Inventors: 李明
Original assignee: Chengdu Taimai Technology Co ltd
Current assignee: Chengdu Taimai Technology Co ltd
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2023-08-22
Anticipated expiration: 2033-03-22

Abstract

The utility model discloses a Q-band broadband orthogonal mode coupler, wherein the working frequency band covers 37 GHz-53 GHz, and the relative bandwidth is more than 35.5%. In the working frequency band, the voltage standing wave ratio of the horizontal polarization output port and the vertical polarization output port is smaller than 1.15, the port isolation is larger than 40dB, the insertion loss is smaller than 0.3dB, and the device belongs to the design of high-performance broadband waveguide devices. The Q-band broadband orthogonal mode coupler comprises a public square waveguide, a special-shaped ladder waveguide and a side arm waveguide. The caliber of the public square waveguide is smaller than the long side size of the standard BJ400 rectangular waveguide; the special-shaped step waveguide consists of 1 special-shaped fourth-order square moment transition waveguide and 1 standard BJ400 rectangular waveguide; the side arm waveguide consists of 2 cascaded T-shaped waveguides and 1 standard BJ400 rectangular waveguide, and the T-shaped waveguide is arranged on one side step surface of the special-shaped fourth-order square moment transition waveguide. The Q-band broadband orthogonal mode coupler has the beneficial effects of simple structure, convenience in processing, no need of other allocation measures, two output ports are standard rectangular waveguides, and the Q-band broadband orthogonal mode coupler is suitable for broadband high-power antenna feeds above 30 GHz.

Description

Q frequency band broadband quadrature mode coupler

Technical Field

The utility model relates to an orthogonal mode coupler in the technical field of satellite communication and measurement and control antennas, in particular to a broadband high-performance orthogonal mode coupler which works in a Q frequency band, the frequency band range covers 37 GHz-53 GHz, the relative bandwidth is more than 35.5%, the structure is compact, the processing is simple, and debugging is avoided.

Background

The orthogonal mode coupler, OMT for short, is one basic element in satellite communication and measurement and control antenna system and is used in realizing the polarization discrimination and signal separation of two orthogonal electric field direction mode signals input via common port. For an orthomode coupler, the working bandwidth, port standing waves and isolation are key technical indexes for determining the performance of the orthomode coupler. Through decades of intensive researches by researchers in the field of antennas, the design technology of the orthogonal mode coupler is well-established, and related documents and patents such as Heng river sand numbers are also adopted. Based on the advantages of low loss and high power capacity of waveguide feeders, quadrature mode couplers in the form of waveguides are one of the most commonly used types in antenna systems. Currently, the research direction and hot spot of quadrature mode couplers is to achieve higher frequencies and wider frequency bands. Meanwhile, on the basis of the existing design scheme and technology, through optimization or innovation of the device structure, the electrical performance is improved, the processing difficulty is reduced, and the debugging-free capability of the device is realized.

The utility model patent with the name of Ku-band broadband orthomode coupler with the Chinese patent application number of 201710206900.5 discloses a broadband orthomode coupler with a square wave guide mode, the working frequency band of 10.7 GHz-14.5 GHz and the relative bandwidth of 30.16%. The output port of the branch waveguide of the orthogonal mode coupler and the output port of the tail end of the square moment conversion section are non-standard waveguide ports, the port size is smaller than that of a standard waveguide interface of the BJ120 and the BJ140, in practical application, if the output port is required to be transitionally enlarged to be a standard waveguide port, the structural complexity of the whole device is increased, the electrical performance of the device is reduced, and in an antenna system with the interface requiring the standard waveguide port, the advantages of compact structure and small size are difficult to embody. Meanwhile, as shown in the standing wave curve results of the output port shown in the drawing (figure 2) of the patent specification, in the frequency band of 10.7 GHz-14.5 GHz, standing waves of two ports are smaller than 1.36, when the relative bandwidth exceeds 31%, the standing wave performance is rapidly deteriorated, and the relative bandwidth of more than 35% cannot be realized.

The utility model patent with the name of a quadrature mode coupler and a design method in China patent application number 20221028502.4 discloses a Ku frequency band quadrature mode coupler in a circular waveguide mode. The orthogonal mode coupler adopts a circular waveguide as a common port; the straight-through rectangular port is a transmitting port, and the working frequency is 13.6 GHz-14.6 GHz; the rectangular port of the side arm is a receiving port, and the working frequency is 10.7 GHz-12.8 GHz. The orthogonal mode coupler realizes the function of orthogonal coupling of two ends which are received and transmitted in the Ku frequency band, and two rectangular ports cannot meet the working requirements of 10.7 GHz-14.6 GHz full frequency bands at the same time, thereby belonging to the field of narrow-band application.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model provides the Q-band broadband orthogonal mode coupler which is innovatively designed, and has the advantages of compact structure, easiness in processing, no need of debugging, good electrical properties such as port standing wave, isolation, insertion loss, power capacity and the like in the working frequency band with the relative bandwidth being more than 35.5%. Meanwhile, the Q-band broadband quadrature mode coupler can be applied to other frequency bands through equal-ratio scaling.

In order to solve the technical problems, the utility model adopts the following technical scheme:

a Q-band broadband orthogonal mode coupler is composed of a public square waveguide (1), a special-shaped ladder waveguide (2) and a side arm waveguide (3). The port A of the public Fang Bodao (1) is a signal input port of the Q-band broadband orthogonal mode coupler, and a waveguide port of the public Fang Bodao (1) opposite to the port A is connected with a square wave guide port of the special-shaped step waveguide (2); the special-shaped stepped waveguide (2) consists of a special-shaped fourth-order square moment transition waveguide (21) and a standard BJ400 rectangular waveguide (22), and an output port B of the standard BJ400 rectangular waveguide (22) is a Q-band broadband orthogonal mode coupler vertical polarization output port; the side arm waveguide (3) consists of a first-stage T-shaped waveguide (31), a second-stage T-shaped waveguide (32) and a standard BJ400 rectangular waveguide (33), the side arm waveguide (3) is arranged on the upper surface stepped surface of the special-shaped fourth-stage square moment transition waveguide (21) through the first-stage T-shaped waveguide (31), and an output port C of the standard BJ400 rectangular waveguide (33) is a horizontal polarization output port of the Q-band broadband orthogonal mode coupler.

In the above structure, the side length of the port a of the common Fang Bodao (1) is smaller than the long side sizes of the standard BJ400 rectangular waveguide (22) and the standard BJ400 rectangular waveguide (33).

In the structure, the input port of the special-shaped step waveguide (2) is a square wave guide port, and the port size is the same as the port A of the public Fang Bodao (1). The special-shaped step waveguide (2) is in an axisymmetric graph from the lower view in the upper surface direction. The upper surface and the lower surface of the special-shaped fourth-order square moment transition waveguide (21) are of a ladder structure, the upper surface is of a three-stage ladder, the lower surface is of a four-stage ladder, and the ladder width is equal to the side length of a port A of the public Fang Bodao (1). The four steps on the lower surface of the special-shaped four-step square moment transition waveguide (21) are a step (211), a step (212), a step (213) and a step (214) respectively. The three steps on the upper surface of the special-shaped fourth-order square moment transition waveguide (21) are a step (215), a step (216), a step (217) and a step (214) respectively. The length of the step (211) is equal to the length of the step (215), and the height of the step (211) is larger than the height of the step (215). The length of the step (212) is equal to the length of the step (216), and the height of the step (212) is greater than the height of the step (216). The sum of the lengths of steps (213) and (214) is equal to the length of step (217).

In the structure, a rectangular groove (218) is formed in the connecting end face of the step (217) and the step (216) of the special-shaped fourth-order square moment transition waveguide (21), the lower surface of the rectangular groove (218) is coplanar with the step (216), and the left surface of the rectangular groove (218) is coplanar with the left end face of the step (213).

In the structure, the first-stage T-shaped waveguide (31), the second-stage T-shaped waveguide (32) and the standard BJ400 rectangular waveguide (33) of the side arm waveguide (3) are sequentially cascaded. The front views of the side arm waveguides (3) are all axisymmetric patterns. The first stage T-shaped waveguide (31) has a smaller structural dimension than the second stage T-shaped waveguide (32). The lower structure of the first-stage T-shaped waveguide (31) can be tightly fitted at the rectangular groove (218) of the special-shaped fourth-order square moment transition waveguide (21).

In the structure, the public Fang Bodao (1), the special-shaped ladder waveguide (2) and the side arm waveguide (3) are all air cavities, and in practical engineering application, after the Q-band broadband orthogonal mode coupler is formed by the public Fang Bodao (1), the special-shaped ladder waveguide (2) and the side arm waveguide (3), other outer surface boundaries except the port A, the port B and the port C are all metal.

In the above structure, the standard BJ400 rectangular waveguide (22) and the standard BJ400 rectangular waveguide (33) are both standard rectangular waveguides performing the standard GB 11450.2-89.

In the above configuration, the electric field directions of the ports B and C are orthogonal.

The working principle of the utility model is as follows:

according to the working principle of the orthogonal mode coupler, when signals are input from a public port A of a public square waveguide (1), through the short circuit effect of steps of a special-shaped step waveguide (2) and the coupling effect of a first-stage T-shaped waveguide (31) of a side arm waveguide (3), a port B of the special-shaped step waveguide (2) and a port A of the side arm waveguide (3) can respectively output one path of vertically polarized microwave signals and one path of horizontally polarized microwave signals, so that polarization identification and separation of two paths of orthogonal polarized signals are realized. The Q-band broadband orthogonal mode coupler widens the working bandwidth of the orthogonal mode coupler and realizes the working bandwidth which cannot be realized by the compact orthogonal mode coupler in the technical field of current antenna feed source design by innovatively designing the asymmetric steps of the special-shaped fourth-order square moment transition waveguide (21) in the special-shaped step waveguide (2) and the two-stage cascade structures of the first-stage T-shaped waveguide (31) and the second-stage T-shaped waveguide (32) in the side arm waveguide (3). The Q-band broadband orthogonal mode coupler adopts the standard BJ400 rectangular waveguide (22) and the standard BJ400 rectangular waveguide (33) as output ports, can be conveniently connected with amplifier equipment of a standard interface, and is convenient for the Q-band broadband orthogonal mode coupler to be applied to practical antenna engineering.

The utility model is not described in detail in part as being common general knowledge to a person skilled in the art.

Compared with the background technology, the utility model has the advantages of simple structure, convenient processing, small size, high precision, excellent electrical performance and the like, and realizes the working bandwidth of 35.5%.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is a perspective view of the structure of the present utility model.

Fig. 3 is a structural perspective view of the profiled step waveguide (2) of the present utility model.

Fig. 4 is a structural lower view of the profiled step waveguide (2) of the present utility model.

Fig. 5 is a structural front view of the profiled step waveguide (2) of the present utility model.

Fig. 6 is a perspective view of the structure of the side arm waveguide (3) of the present utility model.

Fig. 7 is a front view of the structure of the side arm waveguide (3) of the present utility model.

Fig. 8 is a left side view of the structure of the side arm waveguide (3) of the present utility model.

Fig. 9 is a front elevational view of the structure of the present utility model.

Fig. 10 is a structural lower view of the present utility model.

Fig. 11 is a standing wave simulation result of the present utility model.

FIG. 12 is a simulation result of the port isolation of the present utility model.

Fig. 13 is a simulation result of the insertion loss of the present utility model.

Description of the embodiments

According to the design method of the Q-band broadband orthomode coupler, the broadband orthomode coupler working in the Q-band (37 GHz-53 GHz) is designed, wherein the size of the public Fang Bodao (1) port A is 4.45mm multiplied by 4.45mm. The special-shaped step waveguide (2) and the side arm waveguide (3) are standard BJ400 rectangular waveguides of the implementation standard GB 11450.2-89, and the caliber of the waveguide is 5.69mm multiplied by 2.845mm. The length of the whole Q-band broadband orthomode coupler is 17mm, and the maximum size in the width direction is 13mm. The Q-band broadband orthogonal mode coupler is simulated in microwave professional simulation software CST, standing waves of two output ports are better than 1.15 in the working bandwidth of 37 GHz-53 GHz, the port isolation is greater than 40dB, the insertion loss is less than 0.3dB, and the engineering application requirements are met.

It will be appreciated by those skilled in the art that the foregoing detailed description has been given for the purpose of providing a reader with the principles of the utility model, and it is intended that the scope of the utility model is not limited to such specific embodiments, but is intended to cover various modifications or adaptations within the scope of the utility model as would be set forth in the following claims.

Claims

1. A Q-band broadband orthogonal mode coupler is characterized by comprising a public square waveguide (1), a special-shaped ladder waveguide (2) and a side arm waveguide (3). The port A of the public Fang Bodao (1) is a signal input port of the Q-band broadband orthogonal mode coupler, and a waveguide port of the public Fang Bodao (1) opposite to the port A is connected with a square wave guide port of the special-shaped step waveguide (2); the special-shaped stepped waveguide (2) consists of a special-shaped fourth-order square moment transition waveguide (21) and a standard BJ400 rectangular waveguide (22), and an output port B of the standard BJ400 rectangular waveguide (22) is a Q-band broadband orthogonal mode coupler vertical polarization output port; the side arm waveguide (3) consists of a first-stage T-shaped waveguide (31), a second-stage T-shaped waveguide (32) and a standard BJ400 rectangular waveguide (33), the side arm waveguide (3) is arranged on the upper surface stepped surface of the special-shaped fourth-stage square moment transition waveguide (21) through the first-stage T-shaped waveguide (31), and an output port C of the standard BJ400 rectangular waveguide (33) is a horizontal polarization output port of the Q-band broadband orthogonal mode coupler.

2. The Q-band broadband quadrature mode coupler of claim 1, wherein the input port of the shaped step waveguide (2) is a square wave guide port, and the port size is the same as the port a of the common Fang Bodao (1). The special-shaped step waveguide (2) is in an axisymmetric graph from the lower view in the upper surface direction. The upper surface and the lower surface of the special-shaped fourth-order square moment transition waveguide (21) are of a ladder structure, the upper surface is of a three-stage ladder, the lower surface is of a four-stage ladder, and the ladder width is equal to the side length of a port A of the public Fang Bodao (1). The four steps on the lower surface of the special-shaped four-step square moment transition waveguide (21) are a step (211), a step (212), a step (213) and a step (214) respectively. The three steps on the upper surface of the special-shaped fourth-order square moment transition waveguide (21) are a step (215), a step (216), a step (217) and a step (214) respectively. The length of the step (211) is equal to the length of the step (215), and the height of the step (211) is larger than the height of the step (215). The length of the step (212) is equal to the length of the step (216), and the height of the step (212) is greater than the height of the step (216). The sum of the lengths of steps (213) and (214) is equal to the length of step (217).

3. The Q-band broadband orthogonal mode coupler according to claim 1, wherein a rectangular groove (218) is formed on a connection end surface of the step (217) and the step (216) of the special-shaped fourth-order square moment transition waveguide (21), a lower surface of the rectangular groove (218) is coplanar with the step (216), and a left surface of the rectangular groove (218) is coplanar with a left end surface of the step (213).

4. The Q-band broadband quadrature mode coupler according to claim 1, wherein the first stage T-shaped waveguide (31), the second stage T-shaped waveguide (32) and the standard BJ400 rectangular waveguide (33) of the side arm waveguide (3) are in a cascade structure in order. The front views of the side arm waveguides (3) are all axisymmetric patterns. The first stage T-shaped waveguide (31) has a smaller structural dimension than the second stage T-shaped waveguide (32). The lower structure of the first-stage T-shaped waveguide (31) can be tightly fitted at the rectangular groove (218) of the special-shaped fourth-order square moment transition waveguide (21).

5. The Q-band broadband orthogonal mode coupler according to claim 1, wherein the common Fang Bodao (1), the special-shaped step waveguide (2) and the side arm waveguide (3) are all air cavities, and in practical engineering application, after the Q-band broadband orthogonal mode coupler is formed by the common Fang Bodao (1), the special-shaped step waveguide (2) and the side arm waveguide (3), other outer surface boundaries except for the port a, the port B and the port C are all metal.

6. A Q-band wideband quadrature mode coupler as claimed in claim 1, wherein the side length of the port a of the common Fang Bodao (1) is smaller than the long side dimensions of the standard BJ400 rectangular waveguide (22) and the standard BJ400 rectangular waveguide (33).

7. A Q-band wideband quadrature mode coupler as claimed in claim 1, wherein the standard BJ400 rectangular waveguide (22) and the standard BJ400 rectangular waveguide (33) are standard rectangular waveguides implementing standard GB 11450.2-89.

8. The Q-band wideband quadrature mode coupler of claim 1, wherein the operating band is 37 ghz-53 ghz, and the relative bandwidth is greater than 35.5%, and the Q-band wideband quadrature mode coupler is applicable to other bands by scaling.