CN216698694U

CN216698694U - Millimeter wave waveguide coaxial microstrip conversion structure

Info

Publication number: CN216698694U
Application number: CN202220343128.8U
Authority: CN
Inventors: 宋星; 顾伟; 袁光辉; 康育贵; 陈国维
Original assignee: Aerospace Science And Technology Microsystem Technology Co ltd
Current assignee: Aerospace Science And Technology Microsystem Technology Co ltd
Priority date: 2022-02-21
Filing date: 2022-02-21
Publication date: 2022-06-07
Anticipated expiration: 2032-02-21

Abstract

The utility model relates to a millimeter wave waveguide coaxial microstrip conversion structure which comprises a rectangular waveguide cavity, a radio frequency insulator, an air coaxial line and a microstrip line, wherein the microstrip line is positioned in a microstrip air cavity, the radio frequency insulator comprises an insulator outer conductor and an insulator inner conductor penetrating through the axis of the insulator outer conductor, one end of the insulator inner conductor penetrates through the side wall of the rectangular waveguide cavity and is connected with a coaxial cylinder in the rectangular waveguide cavity, the other end of the insulator inner conductor penetrates through the air coaxial line and is connected with the microstrip line through a gold band, the right end of the insulator outer conductor is positioned through the left end of the air coaxial line and is sintered on the microstrip air cavity, and the left end of the insulator outer conductor is flush with the side wall of the rectangular waveguide cavity. The utility model has compact structure, wide frequency band and good sealing performance; the impedance of the high-impedance waveguide is reduced, so that impedance matching can be performed on the microstrip line after conversion; compared with gold wires, the method can control the impedance and phase consistency among the same components.

Description

Millimeter wave waveguide coaxial microstrip conversion structure

Technical Field

The utility model relates to the technical field of waveguide coaxial conversion, in particular to a millimeter wave waveguide coaxial microstrip conversion structure.

Background

In the millimeter wave system, in order to reduce propagation loss and suppress higher order modes, the waveguide system replaces the coaxial system and is directly connected with the microstrip circuit. The rectangular waveguide has the characteristics of large power capacity, small loss, no radiation loss, high Q value and the like, and is widely applied to long-distance transmission systems in microwave and millimeter wave circuits and systems, so that the waveguide microstrip is converted into a very important device structure in the millimeter wave system, and the key indexes of the waveguide microstrip, namely standing wave and insertion loss, directly influence various parameters of the system, such as noise coefficient, power and the like. At present, a plurality of transition structures of rectangular waveguide-microstrip are provided, and typical forms of the transition structures are as follows: the transition conversion circuits are based on the mode of electric field excitation in the rectangular waveguide, and complete the electromagnetic field mode conversion between the main modes of the rectangular waveguide and the microstrip line, so that the transmission of electromagnetic signals between two different propagation media is realized. In high-frequency and high-power occasions, especially in power amplifier components in millimeter wave frequency bands, in order to meet low loss, radio frequency interfaces are often in a waveguide form.

In the semiconductor process, required components and circuits are manufactured in a small area by growing epitaxy on a certain substrate material and performing photoetching, corrosion and other methods, so that all chips produced by the method are bare chips. Bare chips cannot be exposed to an external humid, dusty environment for a long time, and different forms of packaging are required. Because millimeter wave circuit size is little, and is highly required to the machining precision to the miniaturized requirement of electronic equipment components and parts now, the naked chip of non-encapsulation will be used in a large number in the millimeter wave subassembly. The rectangular waveguide is an open/semi-open structure, and external moisture, impurities and the like can enter the assembly through the waveguide cavity, so that the reliability of the bare chip is influenced. Therefore, the airtightness of the assembly prevents external moisture and impurities from affecting components in the assembly, and the reliability of the chip in long-term use can be improved.

SUMMERY OF THE UTILITY MODEL

The utility model provides a millimeter wave waveguide coaxial microstrip conversion structure for solving the technical problem.

In order to achieve the purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides a coaxial microstrip transform structure of millimeter wave waveguide, includes rectangular waveguide chamber, radio frequency insulator, air is coaxial and microstrip line, the microstrip line is arranged in the microstrip air chamber, the radio frequency insulator includes insulator outer conductor and runs through the insulator inner conductor of insulator outer conductor axis, the lateral wall that the one end of insulator inner conductor passed rectangular waveguide chamber is connected with coaxial cylinder in the rectangular waveguide intracavity, and the other end of insulator inner conductor passes the air and is coaxial and connect the microstrip line through the gold area, and the right-hand member of insulator outer conductor passes through the coaxial left end location of air, and the sintering is on the microstrip air chamber, the left end of insulator outer conductor flushes with the lateral wall in rectangular waveguide chamber.

Furthermore, the rectangular waveguide cavity through which the conductor in the insulator passes and the input port of the rectangular waveguide are positioned on the adjacent side faces.

Further, the rectangular waveguide is a height-reducing waveguide.

Further, it is characterized in that: the gold belt wraps the other end of the insulator inner conductor.

Furthermore, the connection mode of the gold band and the microstrip line is crimping or welding.

Furthermore, the microstrip line is a copper-clad strip on the surface of the dielectric plate.

Furthermore, the microstrip air cavity is a hollow rectangular metal cavity.

Compared with the prior art, the utility model has the following beneficial effects:

1. the utility model has compact structure, wide frequency band and good sealing performance, and can meet the sealing requirement of actual engineering;

2. the utility model reduces the waveguide impedance to be smaller, and is easier to carry out impedance matching on the microstrip line after conversion;

3. the utility model connects the insulator inner conductor and the microstrip line by the way of the gold-wrapped belt, and compared with the gold wire, the utility model can control the impedance and phase consistency among the same components.

Drawings

FIG. 1 is a schematic perspective view of the structure of the present invention;

FIG. 2 is a schematic plan perspective view of the present invention;

FIG. 3 is a graph of insertion loss simulation results;

FIG. 4 is a graph of return loss simulation results;

FIG. 5 is a graph of input standing wave simulation results;

the attached drawings are as follows: 1-rectangular waveguide cavity, 2-waveguide short-circuit surface, 3-input port, 4-coaxial cylinder, 5-insulator inner conductor, 6-insulator outer conductor, 7-air coaxial, 8-gold band, 9-microstrip air cavity, 10-microstrip line and 11-dielectric plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.

Example one

As shown in fig. 1 and 2, the millimeter wave waveguide coaxial microstrip transition structure disclosed by the present invention comprises a rectangular waveguide cavity 1, a radio frequency insulator, an air coaxial 7 and a microstrip line 10, wherein the microstrip line 10 is located in a microstrip air cavity 9, the radio frequency insulator comprises an insulator outer conductor 6 and an insulator inner conductor 5 penetrating through the axis of the insulator outer conductor 6, one end of the insulator inner conductor 5 penetrates through the sidewall of the rectangular waveguide cavity 1 and is connected with a coaxial cylinder 4 in the rectangular waveguide cavity 1, the other end of the insulator inner conductor 5 penetrates through the air coaxial 7 and is connected with the microstrip line 10 through a gold ribbon 8, the right end of the insulator outer conductor 6 is positioned through the left end of the air coaxial 7 and is sintered on the microstrip air cavity 9, and the left end of the insulator outer conductor 6 is flush with the sidewall of the rectangular waveguide cavity 1.

The rectangular waveguide cavity 1 through which the insulator inner conductor 5 passes and the input port 3 of the rectangular waveguide are positioned on the adjacent side surfaces. The top surface of the rectangular waveguide cavity 1 is a waveguide short-circuit surface 2, and the bottom surface is an input port 3 of the rectangular waveguide. After the radio frequency signal enters from the input port 3, the strongest antinode of the electric field is formed at the center of the coaxial cylinder 4 through the reflection of the waveguide short-circuit surface 2.

Both the coaxial cylinder 4 and the air-coaxial 7 are used for conducting electromagnetic signals.

The rectangular waveguide is a height-reducing waveguide.

The other end of the insulator inner conductor 5 is wrapped by the gold belt 8, and the gold belt is fixed at the right end of the insulator inner conductor 5 through compression molding.

The connection mode of the gold strip 8 and the microstrip line 10 is crimping or welding.

The microstrip line 10 is a copper-clad tape on the surface of the dielectric plate 11. The dielectric plate 11 is arranged on the bottom surface of the inner cavity of the microstrip air cavity 9, the dielectric plate 11 is Rogers 5880, and the microstrip line 10 is a microwave transmission line formed by a single conductor strip supported on the dielectric plate 11.

The microstrip air cavity 9 is a hollow rectangular metal cavity.

The rectangular waveguide cavity 1 and the microstrip air cavity 9 are both made of hollow aluminum alloy materials.

Example two

On the basis of the first embodiment, the present embodiment provides a specific implementation process of a millimeter wave waveguide coaxial microstrip transition structure.

The specific implementation principle flow is as follows:

the radio frequency signal enters from the height reducing waveguide port and is reflected at the center of the coaxial cylinder through the short-circuit surface of the waveguide to form the strongest antinode of the electric field. The radio frequency signal is transmitted to the microstrip line in the microstrip air cavity through the insulator inner conductor, so that the mode conversion of the electromagnetic field between the rectangular waveguide and the microstrip line is completed, and the electromagnetic signal is transmitted between two different transmission media. The embodiment has compact structure, wide frequency band and good sealing property, and can meet the sealing requirement of actual engineering.

The impedance of the high waveguide is reduced, so that impedance matching can be performed on the microstrip line after conversion. The coaxial and microstrip lines in the insulator are connected in a gold-wrapped manner, so that the impedance and phase consistency among the same components can be controlled compared with gold wires.

As shown in FIGS. 3, 4 and 5, simulation results show that the insertion loss is less than 0.1dB and the standing wave is less than 1.2 in the frequency range of 26 GHz-44 GHz.

In addition, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict. The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

In the description of the present invention, it is to be understood that the terms "longitudinal," "lateral," "length," "width," "thickness," "diameter," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like, refer to the orientation or positional relationship illustrated in the drawings, which is referenced herein for convenience and simplicity of description, and do not indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, is not to be considered as limiting.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the utility model be considered as within the following claims.

Claims

1. A millimeter wave waveguide coaxial microstrip transition structure is characterized in that: including rectangular waveguide chamber, radio frequency insulator, air are coaxial and microstrip line, the microstrip line is arranged in the microstrip air cavity, the radio frequency insulator includes insulator outer conductor and runs through the insulator inner conductor of insulator outer conductor axis, the lateral wall that rectangular waveguide chamber was passed to the one end of insulator inner conductor is connected with coaxial cylinder in the rectangular waveguide intracavity, and the other end of insulator inner conductor passes the air and is coaxial and connect the microstrip line through the gold area, and the right-hand member of insulator outer conductor passes through the coaxial left end location of air, and the sintering is on the microstrip air cavity, the left end of insulator outer conductor flushes with the lateral wall in rectangular waveguide chamber.

2. The millimeter wave waveguide coaxial microstrip transition structure of claim 1, wherein: the rectangular waveguide cavity through which the conductor in the insulator passes and the input port of the rectangular waveguide are positioned on the adjacent side surfaces.

3. The millimeter wave waveguide coaxial microstrip transition structure of claim 1, wherein: the rectangular waveguide is a height-reducing waveguide.

4. A millimeter wave waveguide coaxial microstrip transition structure according to any one of claims 1 to 3, characterized in that: and the other end of the insulator inner conductor is wrapped by the gold band.

5. The millimeter wave waveguide coaxial microstrip transition structure of claim 4, wherein: the connection mode of the gold band and the microstrip line is crimping or welding.

6. The millimeter wave waveguide coaxial microstrip transition structure of claim 1, wherein: the microstrip line is a copper-clad strip on the surface of the dielectric plate.

7. The millimeter wave waveguide coaxial microstrip transition structure of claim 1, wherein: the microstrip air cavity is a hollow rectangular metal cavity.