A 3 chip GaAs double conversion TV tuner system with 70 dB image rejection

A fully integrated three-chip VHF-UHF TV tuner system is presented that uses 0.7- mu m MESFET GaAs technology. The system, based on the double frequency conversion method, consists of an upconverter (IF/sub 1/=1.9 GHz), a smoothing filter, and an image rejection downconverter (IF/sub 2/=35 MHz) connected together on an alumina substrate. The total conversion gain is 30 dB and the rejection level is more than 60 dB throughout the VHF-UHF band with only one preliminary trimming at 500 MHz. Upconverter narrowband amplifier, image frequency rejection mixer (IFRM), and phase shifter measurements data are provided.<
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