MICROWAVE MIXER ON RECTANGULAR WAVEGUIDES PARTIALLY FILLED BY DIELECTRIC

Abstract

The article investigates and calculates the characteristics of microwave mixers on rectangular waveguides partially filled by dielectric. Presents diagrams of promising combined microwave radio engineering systems - two options for constructing mobile digital troposcatter-radiorelay stations, the antenna-feeder paths of which are implemented on rectangular waveguides partially filled by dielectric. At research of microwave mixers, suppression and the use of the mirror frequency are taken into account. The analysis of researches of microwave mixers is carried out. The design of a balanced-type microwave mixer based on rectangular waveguides partially filled by dielectric is developed. The mixer is used to convertion the microwave signal into an intermediate frequency signal. The signal conversion of the mixers takes place on the non-linear active resistance of the semiconductor diode. In article, an open nonlinear structure is used as such a diode. The following main parameters of microwave mixers are investigated: conversion losses, noise factor, operating frequency band, signal suppression at the mirror frequency. The conversion losses are determined for various mirror channel suppression conditions. Phase methods of mirror frequency suppression are considered, which are most suitable for the waveguide implementation of microwave mixers. A scheme of a microwave mixer of a balance type with a phase method for suppressing the mirror frequency is presented. The article notes that for significant suppression of the mirror frequency of more than 30 dB, a double frequency conversion mixer is used. A diagram of a slotted bridge based on rectangular waveguides partially filled by dielectric is presented. The dependences of the input impedance of the mixer, the impedance of the mixer at the intermediate frequency, the impedance of the mixer at the mirror frequency by the power of the local heterodyne are plotted.