An l-band four-ridge quadrature-mode coupler

Abstract

The invention relates to an L-band four-ridge orthogonal mode coupler. The orthogonal mode coupler is a modified exponential gradient curve loaded with a ridge membrane and a coaxial excitation structure. The working frequency is 1-2GHz, and it is applied to the L-band reception of radio telescopes. machine system. The orthogonal mode coupler is composed of a circular waveguide, a four-ridge waveguide gradual transition section, a four-ridge circular waveguide, a ridge diaphragm, a short-circuit back cavity, a first coaxial probe and a second coaxial probe. Working frequency design; the modified exponential gradient impedance transformation method is used in the four-ridge waveguide gradual change section to ensure the transmission from the main mode of the four-ridge circular waveguide to the main mode of the circular waveguide; the chamfering correction is performed on the four-ridge section in the four-ridge circular waveguide to ensure There will be no mutual interference between the ridge diaphragms; the four-ridge waveguide coaxial converter adopts the coaxial feeding method, and its short-circuit back cavity adopts a conical design. The measured reflection loss and isolation of the orthogonal mode coupler are basically consistent with the simulated results, which can meet the needs of radio astronomy observations.

Description

technical field [0001] The invention relates to an L-band four-ridge quadrature mode coupler, which is specially used for a wideband microwave receiver in the field of radio astronomy. Background technique [0002] Ortho-Mode Transducer (OMT, Ortho-Mode Transducer), as an important part of dual-polarization antenna feeder system, has been widely used in satellite communication, radio astronomy and military radar. In the field of radio astronomy, the widening of the OMT operating frequency band is conducive to the realization of full-band coverage of spectrum resources, which can reduce the division of feed types in each frequency band, improve system efficiency, and reduce equipment costs. [0003] An Orthogonal Mode Coupler (orthogonal or OMT for short) is a separate or hybrid element for two mutually orthogonal polarized waves. OMT can discriminate the independent signals of two orthogonal main modes on a common port (usually a circular waveguide or a square waveguide) an...

AI Technical Summary

Problems solved by technology

[0007] Due to the characteristics of the waveguide mode distribution, even if the first / second high-order mode resonance of the straight channel of the conventional quadrature is eliminated, the working frequency bandwidth of the quadrature cannot be extended to more than twice the frequency band

Therefore, the common fin line OMT, Boifot type partition-branch synthesis OMT, double ridge transition-branch synthesis OMT, double ridge transition-coaxial output OMT, four-arm synthesis OMT, etc. cannot achieve 2:1 octave in engineering. working bandwidth

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