A single MESFET down-converter for TVRO application

Abstract

A compact downconverter for use in TV receive-only (TVRO) receivers is presented. The circuit consists of an image-rejection filter and a self-oscillating mixer performing as a block which converts RF into IF signals. The downconverter's features are fully comparable to those of conventional structures, with the additional advantage that only one MESFET is required, leading to a more compact and reliable design. Average results on a band of 800 MHz (10.95-11.75 GHz with a local oscillator frequency of 10 GHz) gives a conversion gain of 4.5 dB, 8-dB single-sideband (SSB) noise figure, and more than 40-dB image rejection.<>