A study of millimeter-wave GaAs IMPATT oscillator and amplifier noise

Noise characterization of a set of epitaxially grown p-n-junction GaAs IMPATTS that operate efficiently from 26-35 GHz is reported. In oscillator operation, the diodes exhibit an excess noise near the carrier, which follows a 1/
f
dependence. Far from the carrier an AM DSB SNR of 134 dB in a 100-Hz window and an FM noise measure of 36 dB are observed. As a reflection amplifier, a gain of 22 dB with a 250-MHz bandwidth and a noise figure of 25.5 dB is achieved. Under higher gain conditions (28-dB gain) a 24-dB figure is obtained.