Compact multilevel higher harmonic mode multimode filter for rectangular overmoded waveguide

Abstract

The invention discloses a compact multilevel higher harmonic mode multi-mode filter for a rectangular overmoded waveguide and relates to a microwave waveguide element capable of filtering various higher harmonic modes in the rectangular overmoded waveguide in the same frequency while not influencing the pass of a dominant mode basically. Two parallel stampers (2) are arranged in the same cross section of the rectangular overmoded waveguide (1) and positioned on two sides of a narrow wall (3) of an inner cavity respectively; the two stampers (2) form a set of parallel stampers; the height of each stamper (2) in the rectangular overmoded waveguide (1) is equal to that of the narrow wall (3) of the inner cavity of the rectangular overmoded waveguide (1); the width of each stamper (2) is lessthan a half of that of a wide wall (4) of the inner cavity of the rectangular overmoded waveguide (1); the rectangular overmoded waveguide (1) is provided with two or more sets of the parallel stampers (2); and a resonator cell (5) is formed by two adjacent sets of the parallel stampers (2) and a space of the rectangular overmoded waveguide (1) between the two adjacent sets of the parallel stampers (2).

Description

technical field [0001] The invention relates to a microwave waveguide element, in particular to a mode filter capable of simultaneously filtering out multiple high-order modes in a rectangular overmode waveguide. Background technique [0002] Unlike the case where there is only one transmission mode in a single-mode waveguide, and the other high-order modes are all attenuation modes (or fading modes), in an overmode waveguide, there are usually two or more transmission modes. In the same In the working frequency band, the size of the over-mode waveguide is larger than that of the single-mode waveguide. Generally, single-mode waveguides are used, but in many occasions, especially in submillimeter wave or terahertz frequency bands, in order to reduce the transmission loss of the waveguide, or limited by the processing technology, it is necessary to use over-mode waveguides. In the rectangular overmode waveguide, the operating wavelength of the rectangular waveguide is not onl...

AI Technical Summary

Problems solved by technology

In the rectangular overmode waveguide, the operating wavelength of the rectangular waveguide is not only smaller than the working mode, that is, the main mode TE 10 cut-off wavelength, but also smaller than some higher-order modes, such as TE 20 、TE 11 、TM 11 mode or other higher-order modes, so in a rectangular overmode waveguide, not only the main mode can be transmitted, but some higher-order modes such as TE 20 、TE 11 、TM 11 Or other high-order modes can also be transmitted, and these transmitted high-order modes will affect the transmission of the main mode, resulting in a decline in the transmission performance of the main mode. Therefore, it is necessary to suppress or filter out these high-order modes without affecting the transmission of the main mode as much as possible. mold

It is very difficult to filter out high-order modes in a rectangular overmode waveguide. The usual method is to slot or slit the waveguide wall, but usually only one high-order mode can be filtered out by slots or slits.

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