Low noise receiving downconverter

Significant improvements in noise figure and band-width have been obtained in down conversion from frequencies in the 11 GHz range to frequencies of several hundred megacycles. An average noise figure of 5.6 dB and greater than 50 percent bandwidth have been obtained using a Schottky-barrier diode balanced mixer and a low noise transistor preamplifier. We discuss basic design criteria, and present a complete circuit description and measurements for one of the downconverters used in the short hop radio system experiment.