Dual-band high-isolation orthogonal mode coupler

Abstract

The invention discloses a dual-band high-isolation orthogonal mode coupler. A vertical polarization transmitting channel is vertically connected with a horizontal polarization receiving channel. The vertical polarization transmitting channel comprises a common circular waveguide port, a circular-rectangular transition matching network, a square waveguide, a second-order stepped impedance matchingnetwork and a vertical polarization port which are connected successively. Three metal cylinders are arranged in the square waveguide. The horizontal polarization receiving channel comprises an open coupling window and a horizontal polarization port which are connected successively. The open coupling window is connected with the square waveguide and located in front of the metal cylinders. In theinvention, a transmitting frequency band ranges from 13.75 GHz to 14.5 GHz, and a receiving frequency band ranges from 10.7 GHz to 12.75 GHz. A polarization isolation degree in a working frequency band is superior to 55dB, a return loss of each port is less than -20dB, and a passband insertion loss is less than 0.5 dB. The structure is simple, compact and stable and processing is convenient, and the coupler can be widely applied to a radar system of a corresponding frequency band.

Description

technical field [0001] The invention belongs to the field of couplers, in particular to a dual-band high-isolation orthogonal mode coupler. Background technique [0002] Orthogonal mode coupler, referred to as OMT, as an important part of the dual-polarization antenna feeder system, is widely used in radar systems and satellite communications. In the radar system, it can not only enhance the sensitivity of the radar, but also enable the radar to obtain more target structure information, which has far-reaching significance for improving the intelligent information processing capability of the radar detection system. In satellite communication, two channels with different polarization modes and isolated from each other can be used to accommodate more channels on the same frequency; on different frequencies, the isolation of sending and receiving channels can be increased. [0003] At present, the main form of the dual-band dual-polarization orthogonal mode coupler is: the ort...

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Problems solved by technology

[0004] The purpose of the present invention is to propose a dual-band high-isolation orthogonal-mode coupler, which solves the problem that the isolation between the frequency bands of the existing dual-band orthogonal-mode coupler is not high, and an additional filter needs to be introduced, resulting in large size and low insertion loss. bigger problem

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