An active dual-gate GaAs FET mixer for 800 MHz low current consumption mountain top repeaters

Abstract

A dual-gate GaAs FET mixer for use in a low-noise receiver front end in the frequency range of 800 to 900 MHz is presented. The circuit is made on a low-cost 0.062-in fiber glass substrate with in /sub r/ of 4.2 and is designed with inexpensive common surface mount components. The prototype has a third-order intercept of 9 dBm, with respect to the output level, a minimum gain of 13.9 dB, and a sensitivity of -119.3 dBm when driven with an LO power of -2 dBm and with a drain current of 3.0 mA. For improved performance and for easier integration into the receiver, the output impedance is set at 1500 Omega .<>