CN101710638B - Self-temperature compensating rectangular waveguide resonant cavity - Google Patents

Abstract

The self-temperature-compensated rectangular waveguide resonator relates to a waveguide resonator, which can significantly reduce the influence of temperature on the resonant frequency of the resonator. Wherein; the short circuit plate (2) is located in the metal cavity (1), the thermal expansion coefficient of the support body (3) is greater than the thermal expansion coefficient of the metal cavity (1), and the short circuit plate (2) passes through the support body (3) and the metal cavity A top cavity wall (5) of (1) is connected, and the shape of the short circuit plate (3) is similar to the top cavity wall (5), and its size is slightly smaller than the size of the top cavity wall (5); the short circuit plate ( 2), the other top cavity wall (8) of the metal cavity (1), the narrow cavity wall (6) and the wide cavity wall (7) of the metal cavity constitute a resonant space (9) for electromagnetic waves; input The output coupling device (4) is located on the top cavity wall (8) or the narrow cavity wall (6) or the wide cavity wall (7) of the metal cavity (1) in the resonance space (9).

Description

Self-Temperature Compensated Rectangular Waveguide Resonator

technical field

The patent of the present invention relates to a waveguide resonator, especially a self-temperature-compensated rectangular waveguide resonator capable of reducing temperature drift of resonance frequency.

Background technique

The resonant frequency of a waveguide resonant cavity depends on the shape, size, cavity filling medium and resonant mode of the resonant cavity. When the temperature changes, the size of the resonant cavity will also change due to thermal expansion and contraction of the wall material of the resonant cavity, which will cause a change in the resonant frequency of the resonant cavity, which will adversely affect the performance of the resonant cavity. At present, the known methods to reduce the influence of temperature changes on the resonant frequency of the resonator are mainly to adopt constant temperature measures, or use temperature compensation devices, or use cavity materials with small thermal expansion coefficients such as Invar and so on. The main problems of these methods are: the required equipment is complicated, or the magnetic properties of the cavity material limit the application occasions, or additional temperature compensation control devices are required, or the influence of temperature on the resonant frequency of the resonant cavity cannot be greatly reduced.

Contents of the invention

Technical problem: The purpose of the present invention is to propose a self-temperature-compensated rectangular waveguide resonant cavity, which can significantly reduce the influence of temperature changes on the resonant frequency of the resonant cavity.

Technical solution: The self-temperature-compensated rectangular waveguide resonator of the present invention is composed of a metal cavity, a short circuit board, a support body and an input-output coupling device, wherein: the short circuit board is located in the metal cavity; the short circuit board passes through one of the support body and the metal cavity The top cavity wall is connected, its shape is the same as the top surface, and its size is approximately equal to the size of the top cavity wall, but slightly smaller than the top cavity wall, so that the gap between the short circuit board and the four side cavity walls of the metal cavity The gap is very small, which can maintain good electrical contact; the electromagnetic wave resonance occurs in the short circuit board, the other top cavity wall of the metal cavity, the two narrow cavity walls and the two wide cavity walls of the metal cavity In the cuboid resonance space; the resonant frequency of the resonant main mode TE ₁₀₁ mode and the high-order resonant mode TE _m0n is related to the distance from the short circuit board of the metal cavity to the other top cavity wall of the metal cavity without support, and is also related to the resonant cavity one It is related to the distance between the walls of the narrow cavity, the longer these two distances, the lower the resonant frequency of TE ₁₀₁ and TE _m0n modes; the material that constitutes the metal cavity and the short circuit board is a metal material with good electrical conductivity; the support body The thermal expansion coefficient of the material is greater than that of the cavity material; when the temperature rises, due to thermal expansion, the length of the metal cavity in three directions increases, and the length of the support also increases, but because the thermal expansion coefficient of the support material is greater than The thermal expansion coefficient of the metal cavity material, when the ratio of the length of the support to the distance between the top surface of the metal cavity and the wall of the metal cavity is greater than the ratio of the thermal expansion coefficient of the metal cavity material to the thermal expansion coefficient of the support material, the increase in temperature will make the short circuit board The distance between the other top wall of the metal cavity without support is reduced, which can compensate for the change of the resonant frequency caused by the increase in the distance between the two narrow walls of the metal cavity, so the temperature rises Under normal circumstances, the resonant frequencies of the TE ₁₀₁ and TE _m0n modes can be kept basically unchanged; similarly, when the temperature drops, the resonant frequencies of the TE ₁₀₁ and TE _m0n modes can also be kept basically unchanged.

Beneficial effect: the beneficial effect of the present invention is that the variation of the resonant frequency of the rectangular resonant cavity with temperature is greatly reduced, the structure is simple, the applicable frequency range is wide, and no additional temperature compensation control mechanism is required.

Description of drawings

Fig. 1 is a schematic structural view of the present invention.

In the figure, there are a metal cavity 1, a short circuit board 2, a support body 3, an input and output coupling device 4, a cavity wall 5 on the top surface of the cavity connected to the support body, a cavity wall 6 on the narrow side of the cavity, and a cavity wall 7 on the wide side of the cavity , a cavity wall 8 on the top surface of the cavity without a support body, and a resonant space 9 .

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

The technical solution adopted in the present invention is: the self-temperature compensation rectangular waveguide resonant cavity includes a metal cavity, a short circuit board, a support body connecting the bottom surface of the rectangular cavity and the short circuit board, and one or several input and output coupling devices. The shape of the metal cavity can be a cuboid, or a cube with equal narrow and wide sides. The short circuit board is located in the metal cavity. The material of the short circuit board is conductive metal, and metal can also be plated on the surface of non-metallic materials. The short circuit board is connected with a top cavity wall of the metal cavity through the support body. The top surface is similar, and its size is slightly smaller than the size of the top cavity wall. In order to maintain good electromagnetic coupling between the short circuit board and the narrow cavity wall and wide cavity wall of the metal cavity, the short circuit plate and the narrow cavity wall of the metal cavity The gap between the wall and the wide cavity wall is as small as possible, as long as it is guaranteed within the normal operating temperature range, so that the short circuit board cannot slide in the metal cavity. The electromagnetic wave resonance occurs in the cuboid resonance space formed by the short circuit board, another top cavity wall of the metal cavity, two narrow cavity walls and two wide cavity walls of the metal cavity. The input-output coupling device is located on the cavity wall of the metal cavity in the resonant space, and the number of the input-output coupling device can be one or more than one. The resonant frequency of the resonant main mode TE ₁₀₁ mode and the high-order resonant mode TE _m0n is related to the distance from the short circuit board of the metal cavity to the other top cavity wall of the metal cavity without support, and is also related to the distance between a pair of narrow cavity surfaces of the metal cavity. The distance between the walls is related, the longer these two distances, the lower the resonance frequency of TE ₁₀₁ and TE _m0n modes; the material of the support body can be metal or non-metal, such as plastic, etc., and the thermal expansion coefficient of the support body is greater than The thermal expansion coefficient of the metal cavity. When the temperature rises, due to thermal expansion, the length of the metal cavity in three directions increases, and the length of the support body also increases, but because the thermal expansion coefficient of the support body material is greater than that of the metal cavity material, when the support body length and When the ratio of the distance between the top cavity wall of the metal cavity is greater than the ratio of the thermal expansion coefficient of the metal cavity material to the thermal expansion coefficient of the support material, the increase in temperature will cause the short circuit board to the other top cavity of the metal cavity without support. The distance between the walls is reduced, which can compensate for the change of the resonance frequency caused by the increase of the distance between the two narrow walls of the metal cavity, so that when the temperature rises, the resonance frequency of the TE ₁₀₁ and TE _m0n modes can be kept basically unchanged ; Similarly, when the temperature drops, the resonant frequencies of the TE ₁₀₁ and TE _m0n modes can also remain basically unchanged.

Structurally, the self-temperature-compensated rectangular waveguide resonator consists of a metal cavity 1 , a short circuit board 2 , a support 3 and one or several input-output coupling devices 4 . The short circuit board 2 is located in the metal cavity 1, one end of the support body 3 is fixed on the top cavity wall 5 of the metal cavity 1, the other end of the support body 3 is fixed on the short circuit board 2, and the short circuit board 2 passes through the support body 3 and the The top cavity wall 5 of the metal cavity 1 is connected. The short circuit board 2 , the other top cavity wall 8 of the metal cavity 1 , the narrow cavity wall 6 and the wide cavity wall 7 of the metal cavity constitute a resonant space 9 for electromagnetic waves. The input-output coupling device 4 is located on the top cavity wall 8 or narrow cavity wall 6 or wide cavity wall 7 of the metal cavity 1 in the resonant space 9 , and the number of input-output coupling devices can be one or more than one.

In manufacturing, the metal cavity 1 and the short circuit board 2 should be made of materials with good electrical conductivity. The surfaces of the metal cavity 1 and the short circuit board 2 can be plated with gold, and the short circuit board 2 is parallel to the cavity wall 5 on the top surface of the metal cavity. The shape of 2 is similar to the top cavity wall 5, and its size is slightly smaller than the size of the top cavity wall 5. The gap between the short circuit board 2 and the narrow cavity wall 6 and the wide cavity wall 7 of the metal cavity 1 should be as far as possible. Small, as long as it is within the normal operating temperature range, the short circuit board cannot slide in the metal cavity. There can be one or more supports 3, the cross-section of the supports 3 can be circular or other arbitrary shapes, the material of the supports 3 can be metal and non-metal, and the thermal expansion coefficient of the supports 3 is greater than that of the metal cavity 1 coefficient, the ratio of the length of the support body 3 to the distance between the top cavity wall 5 and the top cavity wall 8 of the metal cavity 1 is greater than the ratio of the thermal expansion coefficient of the material of the metal cavity 1 to the thermal expansion coefficient of the support body 3 material, so that the temperature increases , the distance from the short circuit board 2 to the other top cavity wall 8 without support of the metal cavity 1 decreases to compensate for the resonance caused by the increase in the distance between the two narrow cavity walls 6 of the metal cavity 1 due to thermal expansion The frequency changes, so the resonance frequency of the TE ₁₀₁ mode can be kept basically unchanged when the temperature rises or falls. According to the above, the present invention can be realized.

Claims (4)

1. A self-temperature-compensated rectangular waveguide resonator, characterized in that this self-temperature-compensated rectangular waveguide resonator consists of a metal cavity (1), a short circuit board (2), a support body (3) and one or several input-output couplings The device (4) is composed of, wherein; the short circuit board (2) is located in the metal cavity (1), and the short circuit board (2) passes through the support body (3) and a top cavity wall (5) of the metal cavity (1) connected, one end of the support body (3) is fixed on the top cavity wall (5) of the metal cavity (1), the other end of the support body (3) is fixed on the short circuit board (2), and the short circuit board (3) The shape is similar to the top cavity wall (5), and its size is slightly smaller than the size of the top cavity wall (5). The short circuit board (2), the other top cavity wall (8) of the metal cavity (1), The narrow cavity wall (6) and the wide cavity wall (7) of the metal cavity form a resonance space (9) for electromagnetic waves, and the input and output coupling device (4) is located in the metal cavity (1) in the resonance space (9). On the top cavity wall (8) or the narrow cavity wall (6) or the wide cavity wall (7); The thermal expansion coefficient of the metal cavity (1) is smaller than the thermal expansion coefficient of the support body (3). 2. The self-temperature-compensated rectangular waveguide resonator according to claim 1, characterized in that the ratio of the thermal expansion coefficient of the support body (3) material to the thermal expansion coefficient of the metal cavity (1) material is greater than that of the metal cavity (1) top The ratio of the distance between the surface cavity wall (5) to the top cavity wall (8) and the length of the support body (3). 3. The self-temperature-compensated rectangular waveguide resonator according to claim 1, characterized in that between the short circuit board (2) and the narrow cavity wall (6) and wide cavity wall (7) of the metal cavity (1) The gap is as small as possible, as long as the short circuit board (2) cannot slide in the metal cavity (1). 4. The self-temperature-compensated rectangular waveguide resonant cavity according to claim 1, characterized in that the energy of the resonance of the electromagnetic wave exists in the resonant space (9).

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