Waveguide microstrip conversion device and preparation method thereof

Abstract

The waveguide microstrip conversion device comprises a waveguide, one end of a cavity of the waveguide is connected with a microstrip structure in an inserted mode, the microstrip structure comprises a dielectric substrate, a microstrip line and a microstrip circuit board, the microstrip line is arranged on the dielectric substrate, the dielectric substrate is connected with the microstrip circuit board, the dielectric substrate is connected in the waveguide in an inserted mode, and the microstrip circuit board is connected with the waveguide. A shielding plate is further arranged on one side of the waveguide, the microstrip structure penetrates through the shielding plate, an outer circuit board is further arranged on one side of the shielding plate, the outer circuit board is connected with a microstrip circuit board, and a radio frequency connector is connected to the microstrip circuit board. The waveguide and the micro-strip are ingeniously integrated, and the connecting contacts are arranged on the side surface of the micro-strip circuit board and are electrically connected with the external circuit board, so that the occupied space of the circuit board is greatly reduced, and the overall size is reduced; by arranging the shielding plate at one end of the waveguide where the microstrip structure is located, electromagnetic leakage caused by installation of the microstrip is greatly reduced, and the shielding effect of the end is ensured; and the choking coil is arranged to suppress the influence of surface waves and improve the gain.

Description

Technical Field

[0001] The invention belongs to the technical field of waveguide-microstrip conversion, and in particular relates to a waveguide-microstrip conversion device and a preparation method thereof. Background Art

[0002] With the rapid development of microwave devices, microwave integrated circuits have been widely used, and communication equipment has gradually developed in the direction of small size, light weight, high frequency and broadband. As one of the most basic components in the microwave field, the volume, size, weight and transmission characteristics of the transmission line directly or indirectly affect the performance indicators of the communication system. Due to the simple processing and good transmission characteristics of microstrip lines, they are widely used in various microwave circuits, and waveguides are also widely used in microwave and millimeter wave RF fields due to their low-loss transmission characteristics. Therefore, microstrip waveguide conversion has gradually become the most common conversion device in microwave systems.

[0003] However, the existing waveguide-microstrip conversion device often has a large structure, cannot well integrate the waveguide, microstrip and various circuit boards, and is difficult to be applied to smaller devices. Summary of the invention

[0004] The object of the present invention is to provide a waveguide-microstrip conversion device and a preparation method thereof to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a waveguide-microstrip conversion device, comprising a waveguide, wherein one end of the cavity of the waveguide is plugged into a microstrip structure, wherein the microstrip structure comprises a dielectric substrate, a microstrip line and a microstrip circuit board, wherein the microstrip line is arranged on the dielectric substrate, the dielectric substrate is connected to the microstrip circuit board, the dielectric substrate is plugged into the waveguide, a shielding plate is further arranged on one side of the waveguide, the microstrip structure passes through the shielding plate, an external circuit board is further arranged on one side of the shielding plate, the external circuit board is connected to the microstrip circuit board, and a radio frequency connector is connected to the microstrip circuit board.

[0006] Preferably, a choke is provided at one end of the waveguide.

[0007] Preferably, the choke is an annular structure composed of a plurality of sheet plates.

[0008] Preferably, a flange is provided at one end of the waveguide, and an opening on the flange has the same shape as the cross-section of the inner cavity of the waveguide.

[0009] Preferably, a guide post is provided at one end of the waveguide, and one end of the shielding plate is plugged into the guide post.

[0010] Preferably, connection contacts are provided on the side of the microstrip circuit board, the external circuit board is sleeved on the microstrip circuit board, and the external circuit board is electrically connected to the microstrip circuit board via the connection contacts.

[0011] Preferably, it further comprises an external fixing plate, wherein the external fixing plate is arranged on one side of the waveguide, and the shielding plate is arranged inside the external fixing plate.

[0012] A method for preparing a waveguide-microstrip conversion device comprises the following steps:

[0013] 1) A ceramic substrate with a thickness between 0.25 mm and 0.5 mm is selected as a dielectric substrate, a grounding copper-clad layer is provided on the ceramic substrate, and two non-copper-clad areas are provided;

[0014] 2) A 3μm to 7μm metal layer is applied to the surface of the dielectric substrate as a microstrip line to transmit microwave signals from two uncoppered areas to the microstrip line.

[0015] 3) Placing a dielectric substrate covered with a microstrip line in an air cavity to form an air microstrip line structure, wherein one end of the microstrip line is a microstrip coupling port and the other end is a microstrip isolation port;

[0016] 4) attaching the ground copper clad layer of the dielectric substrate to the waveguide cavity to form an integrated structure with the waveguide cavity;

[0017] 5) The shielding plate is clamped on the microstrip circuit board on one side of the dielectric substrate, and the outer end of the shielding plate is clamped on the guide post;

[0018] 6) Connect the external circuit board to the microstrip circuit board, and then fix the external circuit board through the external fixing plate.

[0019] Preferably, the concentric choke disposed at one end of the waveguide is made into a plurality of sheet-like plates by cutting.

[0020] Preferably, the shielding plate and the external circuit board are both provided with openings having the same shape as that of the microstrip circuit board, and the microstrip circuit board is stuck in the openings of the shielding plate and the external circuit board.

[0021] The technical effects and advantages of the present invention are as follows: 1. By cleverly integrating the waveguide and the microstrip, connecting contacts are arranged on the side of the microstrip circuit board to electrically connect with the external circuit board, which greatly reduces the occupied space of the circuit board and reduces the overall volume;

[0022] 2. By setting a shielding plate at one end of the waveguide where the microstrip structure is located, the electromagnetic leakage caused by the installation of the microstrip is greatly reduced, ensuring the shielding effect of this end;

[0023] 3. A choke coil is set to suppress the influence of surface waves and improve gain. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure of the choke coil of the present invention;

[0026] Figure 3 It is a schematic diagram of the explosion structure of the present invention;

[0027] Figure 4 Schematic diagram of the microstrip structure of the present invention.

[0028] In the figure: 1. waveguide; 2. flange; 3. microstrip structure; 31. dielectric substrate; 32. microstrip line; 33. microstrip circuit board; 34. connecting contacts; 4. choke; 5. guide column; 6. shielding plate; 7. external circuit board; 8. external fixing plate; 9. RF connector. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] The present invention provides Figure 1-4 A waveguide-microstrip conversion device shown in the figure comprises a waveguide 1, a choke 4 is arranged at one end of the waveguide 1, and the choke 4 is a ring structure composed of a plurality of sheet plates, which suppresses the influence of surface waves and improves gain. The choke composed of sheet plates can also reduce mutual coupling and further optimize performance; a flange 2 is integrally arranged at one end of the waveguide 1 where the choke 4 is located, and the opening on the flange 2 has the same cross-sectional shape as the inner cavity of the waveguide 1, and the flange 2 plays a connecting role; a microstrip structure 3 is plugged into one end of the cavity of the waveguide 1, and the microstrip structure 3 includes a dielectric substrate 31, a microstrip line 32 and a microstrip circuit board 33, the microstrip line 32 is arranged on the dielectric substrate 31, the dielectric substrate 31 is connected to the microstrip circuit board 33, and the dielectric substrate 31 is plugged into the waveguide 1, and a shielding plate 6 is also arranged on one side of the waveguide 1, and the shielding plate 6 plays a shielding role , which can reduce electromagnetic radiation and provide electromagnetic shielding, and the shielding plate 6 has an opening with the same shape as the microstrip circuit board 33, the gap at the connection is small, and the shielding effect is good. The microstrip structure 3 passes through the shielding plate 6, and an external circuit board 7 is also arranged on one side of the shielding plate 6. A connecting contact 34 is arranged on the side of the microstrip circuit board 33, and the external circuit board 7 is sleeved on the microstrip circuit board 33, and the external circuit board 7 is electrically connected to the microstrip circuit board 33 through the connecting contact 34. When the external circuit board 7 is sleeved on the microstrip circuit board 33, the end surfaces of the two circuit boards are flush, and a radio frequency connector 9 is connected to the microstrip circuit board 33, and also includes an external fixing plate 8, which is arranged on one side of the waveguide 1, and the shielding plate 6 is arranged inside the external fixing plate 8, and the microstrip circuit board 33, the external circuit board 7 and the shielding plate 6 and other components are fixed by the external fixing plate 8.

[0031] A guide post 5 is disposed at one end of the waveguide 1 , and one end of the shielding plate 6 is plugged into the guide post 5 for preliminary fixing of the shielding plate 6 .

[0032] The present invention also provides a method for preparing a waveguide-microstrip conversion device, comprising the following steps:

[0033] 1) A ceramic substrate with a thickness between 0.25 mm and 0.5 mm is selected as a dielectric substrate, a grounding copper-clad layer is provided on the ceramic substrate, and two non-copper-clad areas are provided;

[0034] 2) A 3μm to 7μm metal layer is applied to the surface of the dielectric substrate as a microstrip line to transmit microwave signals from two uncoppered areas to the microstrip line.

[0035] 3) Placing a dielectric substrate covered with a microstrip line in an air cavity to form an air microstrip line structure, wherein one end of the microstrip line is a microstrip coupling port and the other end is a microstrip isolation port;

[0036] 4) The grounded copper clad layer of the dielectric substrate is attached to the waveguide cavity to form an integrated structure with the waveguide cavity; one end of the probe extends into the waveguide to interact with the electromagnetic field in the waveguide, and the other end is connected to the microstrip line to transmit the coupled electromagnetic wave to the microstrip line. In the probe transition structure, the waveguide short-circuit surface is used to form a reflection and form a standing wave with the incident electromagnetic wave, thereby enhancing the coupling effect between the probe and the waveguide;

[0037] 5) The shielding plate is clamped on the microstrip circuit board on one side of the dielectric substrate, and the outer end of the shielding plate is clamped on the guide post;

[0038] 6) Connect the external circuit board to the microstrip circuit board, and then fix the external circuit board through the external fixing plate.

[0039] Specifically, the concentric choke coil disposed at one end of the waveguide is made into a plurality of sheet plates by cutting.

[0040] Specifically, the shielding plate and the external circuit board are both provided with openings having the same shape as that of the microstrip circuit board, and the microstrip circuit board is stuck in the openings of the shielding plate and the external circuit board.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A waveguide-microstrip conversion device, comprising a waveguide (1), characterized in that: A microstrip structure (3) is plugged into one end of the cavity of the waveguide (1); the microstrip structure (3) comprises a dielectric substrate (31), a microstrip line (32) and a microstrip circuit board (33); the microstrip line (32) is arranged on the dielectric substrate (31); the dielectric substrate (31) is connected to the microstrip circuit board (33); the dielectric substrate (31) is plugged into the waveguide (1); a shielding plate (6) is also arranged on one side of the waveguide (1); the microstrip structure (3) passes through the shielding plate (6); an external circuit board (7) is also arranged on one side of the shielding plate (6); the external circuit board (7) is connected to the microstrip circuit board (33); and a radio frequency connector (9) is connected to the microstrip circuit board (33).

2. A waveguide-microstrip conversion device according to claim 1, characterized in that: A choke coil (4) is provided at one end of the waveguide (1).

3. A waveguide-microstrip conversion device according to claim 2, characterized in that: The choke coil (4) is an annular structure composed of a plurality of sheet plates.

4. A waveguide-microstrip conversion device according to claim 1, characterized in that: A flange (2) is provided at one end of the waveguide (1), and an opening on the flange (2) has the same cross-sectional shape as the inner cavity of the waveguide (1).

5. The waveguide-microstrip conversion device according to claim 1, characterized in that: A guide post (5) is provided at one end of the waveguide (1), and one end of the shielding plate (6) is plugged into the guide post (5).

6. A waveguide-microstrip conversion device according to claim 1, characterized in that: A connection contact (34) is provided on the side of the microstrip circuit board (33), the external circuit board (7) is sleeved on the microstrip circuit board (33), and the external circuit board (7) is electrically connected to the microstrip circuit board (33) via the connection contact (34).

7. A waveguide-microstrip conversion device according to claim 1, characterized in that: It also comprises an external fixing plate (8), wherein the external fixing plate (8) is arranged on one side of the waveguide (1), and the shielding plate (6) is arranged inside the external fixing plate (8).

8. A method for preparing a waveguide-microstrip conversion device according to any one of claims 1 to 7, characterized in that: The steps include: 1) A ceramic substrate with a thickness between 0.25 mm and 0.5 mm is selected as a dielectric substrate, a grounding copper-clad layer is provided on the ceramic substrate, and two non-copper-clad areas are provided; 2) A 3μm to 7μm metal layer is applied to the surface of the dielectric substrate as a microstrip line to transmit microwave signals from two uncoppered areas to the microstrip line. 3) Placing a dielectric substrate covered with a microstrip line in an air cavity to form an air microstrip line structure, wherein one end of the microstrip line is a microstrip coupling port and the other end is a microstrip isolation port; 4) attaching the ground copper clad layer of the dielectric substrate to the waveguide cavity to form an integrated structure with the waveguide cavity; 5) The shielding plate is clamped on the microstrip circuit board on one side of the dielectric substrate, and the outer end of the shielding plate is clamped on the guide post; 6) Connect the external circuit board to the microstrip circuit board, and then fix the external circuit board through the external fixing plate.

9. The method for preparing a waveguide-microstrip conversion device according to claim 8, characterized in that: The concentric choke coil arranged at one end of the waveguide is made into a plurality of sheet plates by cutting.

10. The method for preparing a waveguide-microstrip conversion device according to claim 8, characterized in that: The shielding plate and the external circuit board are both provided with openings with the same shape as the microstrip circuit board, and the microstrip circuit board is stuck in the openings of the shielding plate and the external circuit board.

Images