CN101771186B - Self-Temperature Compensated Circular Waveguide TE011 Mode Resonator - Google Patents

Abstract

The invention is a self-temperature-compensated circular waveguide TE ₀₁₁ mode resonant cavity, which can significantly reduce the influence of temperature on the resonant frequency of the resonant cavity. In the resonant cavity, the metal cavity (1) is a hollow cylinder, the short circuit plate (2) is located in the metal cavity (1), and the short circuit plate (2) passes through the connection between the support body (3) and the metal cavity (1). The lower bottom cavity wall (5) is connected, the thermal expansion coefficient of the support body (3) is greater than the thermal expansion coefficient of the metal cavity body (1), and one end of the support body (3) is fixed on the bottom surface cavity wall (5) of the metal cavity body (1). The other end is fixed on the short circuit board (2), the shape of the short circuit board (2) is disc-shaped, and its size is slightly smaller than the size of the bottom cavity wall (5); the short circuit board (2), the metal cavity (1 The cavity wall (6) on the upper bottom surface of ) and the side wall (7) of the metal cavity (1) constitute the resonance space (8) of electromagnetic waves, and the input and output coupling device (4) is located in the metal cavity ( 1) on the side wall (7) or on the cavity wall (6) of the upper bottom surface.

Description

Self-Temperature Compensated Circular Waveguide TE011 Mode Resonator

technical field

The invention relates to a waveguide resonant cavity, in particular to a self-temperature-compensated circular waveguide TE ₀₁₁ mode (also called H ₀₁₁ mode, which is a resonant mode in a circular waveguide resonant cavity) resonance capable of reducing the temperature drift of the resonant frequency cavity.

Background technique

The resonant frequency of the 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 for reducing the influence of temperature changes on the resonant frequency of the resonator are mainly to adopt constant temperature measures, or use additional 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 complex, or an additional temperature compensation control device is 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 this invention is to propose a self-temperature-compensated circular waveguide TE ₀₁₁ mode 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 circular waveguide TE ₀₁₁ mode resonator of the present invention includes a metal cavity, a short circuit board, a support body and one or several input and output coupling devices; wherein, the metal cavity is a hollow cylinder, and the short circuit board Located in the metal cavity, the short circuit board is connected to the lower bottom wall of the metal cavity through the support body. One end of the support body is fixed on the bottom wall of the metal cavity, and the other end is fixed on the short circuit board. The shape of the short circuit board is Disc-shaped, its size is slightly smaller than the size of the bottom cavity wall; the short circuit board, the upper bottom cavity wall of the metal cavity, and the side wall of the metal cavity form a resonance space for electromagnetic waves, and the input and output coupling devices are located in the metal cavity in the resonance space On the side wall of the body or on the cavity wall of the upper bottom surface.

The thermal expansion coefficient of the metal cavity is smaller than that of the support body.

The ratio of the thermal expansion coefficient of the support body material to the thermal expansion coefficient of the metal cavity material is greater than the ratio of the distance between the cavity wall on the lower bottom surface to the cavity wall on the upper bottom surface and the length of the support body.

There is a tight sliding fit between the short circuit board and the side wall of the metal cavity, as long as the short circuit board does not fail to slide in the metal cavity. And within the operating temperature range, thermal expansion will not make these gaps disappear.

The short circuit board is disc-shaped, and it is connected with a bottom cavity wall of a cylindrical metal cavity through a support body, and its size is approximately equal to the size of the bottom cavity wall, but slightly smaller than the bottom cavity wall, so that the short circuit board and the cylindrical metal cavity There is a very small gap between the cavity walls of the cavity. Since the cavity wall current in the resonant mode TE ₀₁₁ mode flows around the circumferential direction of the cavity side wall, the gap between the short circuit board and the metal cavity side wall is not large. The electromagnetic wave affecting the TE ₀₁₁ mode; the electromagnetic wave resonance occurs in the cylindrical resonant space composed of the short circuit board, the other bottom wall of the metal cavity, and the side wall of the metal cavity; the resonant frequency of the resonant mode TE ₀₁₁ mode and the metal cavity The distance between the body short circuit plate and the other bottom cavity wall of the metal cavity without support is also related to the radius of the resonant cavity. The longer these two parameters are, the lower the resonant frequency of the TE ₀₁₁ mode; the formation of the metal cavity and the short circuit The material of the plate is a metal material with good electrical conductivity; the thermal expansion coefficient of the material constituting the support is greater than that of the cavity material; when the temperature rises, the length and radius of the metal cavity increase due to thermal expansion, 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 bottom wall of the metal cavity is greater than the thermal expansion coefficient of the metal cavity material and the thermal expansion of the support material When the ratio of the coefficient is , the increase in temperature will reduce the distance between the short circuit board and the other bottom cavity wall of the metal cavity without support, which can compensate for the increase in the radius of the side wall of the metal cavity and cause the change in resonance frequency, so When the temperature rises, the resonance frequency of the TE ₀₁₁ mode can be kept basically unchanged; similarly, when the temperature drops, the resonance frequency of the TE ₀₁₁ mode can also be kept basically unchanged.

Beneficial effects: the invention greatly reduces the variation of the resonant frequency of the cylindrical resonant cavity with temperature, has simple structure, wide applicable frequency range, and does not need additional temperature compensation control mechanism.

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-output coupling device 4, a lower bottom cavity wall 5, an upper bottom cavity wall 6, a cavity side wall 7, and a resonance space 8.

Detailed ways

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

The self-temperature-compensated circular waveguide TE ₀₁₁ mode resonant cavity includes a metal cavity, a short circuit board, a support body connecting the bottom surface of the cylindrical cavity and the short circuit board, and one or several input and output coupling devices. The shape of the metal cavity is a cylinder. The material of the short circuit board can be the same material as the metal cavity, or other conductive metal materials. It can also be electroplated on the surface of the non-metallic material. The short circuit board is connected to a bottom cavity wall of the metal cavity through the support body, and the short circuit The shape of the board is a disk, and its size is slightly smaller than the size of the bottom cavity wall. The gap between the short circuit board and the side wall of the metal cavity should be as small as possible. As long as it is within the normal operating temperature range, the short circuit board will not fail Just slide in the cavity, because the cavity wall current of the resonant mode TE ₀₁₁ mode flows around the circumferential direction of the cavity side wall, so the gap between the short circuit board and the metal cavity side wall does not affect the electromagnetic wave of the TE ₀₁₁ mode . The electromagnetic wave resonance occurs in the cylindrical resonance space formed by the short circuit board, the other bottom cavity wall of the metal cavity, and the side wall of the metal cavity. The input-output coupling device is located on the cavity wall or side wall of the bottom surface 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 mode TE ₀₁₁ mode is related to the distance from the short circuit board of the metal cavity to the other bottom wall of the metal cavity without support, and is also related to the radius of the cavity wall of the metal cavity. The greater these two parameters, the TE ₀₁₁ The lower the resonance frequency of the mode is; the material of the support body can be metal or non-metal, and the thermal expansion coefficient of the support body is greater than that of the metal cavity. When the temperature rises, due to thermal expansion, the length of the metal cavity in all 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 length of the support body is equal to that of the metal cavity When the ratio of the distance between the cavity walls on the bottom of the 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 distance between the short circuit board and the other bottom cavity wall of the metal cavity without support Decrease can compensate for the change of resonance frequency caused by the increase of the radius of the side wall of the metal cavity, so that when the temperature rises, the resonance frequency of the TE ₀₁₁ mode can be kept basically unchanged; similarly, when the temperature drops, the resonance frequency of the TE ₀₁₁ mode The frequency may also remain substantially unchanged.

Structurally, the self-temperature-compensated circular waveguide TE ₀₁₁ mode resonator consists of a metal cavity 1 , a short circuit board 2 , a support 3 and one or several input-output coupling devices 4 . One end of the support body 3 is fixed on the lower bottom cavity wall 5 of the metal cavity 1, the other end of the support body 3 is fixed on the short circuit board 2, the short circuit board 2 is connected through the bottom cavity wall 5 of the support body 3, and the short circuit board 2 is connected to the bottom surface cavity wall 5 of the support body 3. The cavity walls 5 on the lower bottom surface are parallel, and the shape of the short-circuit plate 2 is a disk, and its diameter is slightly smaller than that of the cavity wall 5 on the lower bottom surface. Since the cavity wall currents in the resonant mode TE ₀₁₁ mode flow around the circumferential direction of the cavity side wall , so the gap between the short circuit board and the side wall of the metal cavity does not affect the electromagnetic waves of the TE ₀₁₁ mode. The short circuit board 2 , the upper bottom cavity wall 6 , and the side wall 7 of the metal cavity 1 constitute a resonant space 8 for electromagnetic waves. The input-output coupling device 4 is located on the upper bottom cavity wall 6 or the side wall 7 of the metal cavity 1 in the resonance space 8 , and the number of the input-output coupling device 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. As small as possible, as long as it is ensured that within the normal operating temperature range, the short circuit board 2 will not be unable to slide in the metal cavity 1, the support body 3 can be one or more, and the cross section of the support body 3 can be circular or other Arbitrary shape, the material of the support body 3 can be metal and non-metal, the thermal expansion coefficient of the support body 3 is greater than the thermal expansion coefficient of the metal cavity 1, the length of the support body 3 and the bottom cavity wall 5 of the metal cavity 1 are between the bottom cavity wall 8 The ratio of the distance is greater than the ratio of the thermal expansion coefficient of the metal cavity 1 material to the thermal expansion coefficient of the support body 3 material, which can be based on the formula for the resonance frequency of the TE ₀₁₁ mode and the material parameters used in the self-temperature-compensated circular waveguide TE ₀₁₁ mode resonant cavity, Specifically calculate the size parameters of the self-temperature-compensated circular waveguide TE ₀₁₁ mode resonant cavity, so that when the temperature increases, the distance between the short circuit board 2 and the cavity wall 6 on the bottom surface of the metal cavity 1 without support decreases to compensate for the metal cavity 1. The radius of the side wall 7 changes the resonant frequency due to the increase of thermal expansion length, so the resonant frequency of the TE ₀₁₁ mode can be kept basically unchanged when the temperature rises or falls. According to the above, the present invention can be realized.

Claims (3)

1. A self-temperature-compensated circular waveguide TE ₀₁₁ mode resonator is characterized in that this self-temperature-compensated circular waveguide resonator comprises a metal cavity (1), a short circuit board (2), a support (3) and one or Several input-output coupling devices (4); wherein, the metal cavity (1) is a hollow cylinder, 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 The lower bottom cavity wall (5) of the metal cavity (1) is connected, one end of the support body (3) is fixed on the lower bottom cavity wall (5) of the metal cavity (1), and the other end is fixed on the short circuit board (2) Above, the shape of the short circuit board (2) is disc-shaped, and its size is slightly smaller than the size of the lower bottom cavity wall (5); the short circuit board (2), the upper bottom cavity wall (6) of the metal cavity (1), The side wall (7) of the metal cavity (1) forms a resonance space (8) for electromagnetic waves, and the input-output coupling device (4) is located on the side wall (7) of the metal cavity (1) in the resonance space (8) or On the cavity wall (6) of the upper bottom surface; 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 circular waveguide TE ₀₁₁ mode 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 bottom cavity The ratio of the distance between the wall (5) to the cavity wall (6) on the upper bottom surface and the length of the support body (3). 3. The self-temperature-compensated circular waveguide TE ₀₁₁ mode resonator according to claim 1, characterized in that the short circuit board (2) and the side wall (7) of the metal cavity (1) are in a tight sliding fit, as long as It is sufficient that the short circuit board (2) cannot slide in the metal cavity (1).

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