PHASE NOISE MEASUREMENTS OF A D-BAND BACKWARD-WAVE OSCILLATOR

The difficulties encountered in measuring phase noise at millimetre wa ve frequencies have resulted in a scarcity of such data for backward w ave oscillators. This paper reports the extension of a highly sensitiv e quasi-optical phase noise measurement system to D-band and presents phase noise spectra of a commercial backward wave oscillator at carrie r frequencies between 120 and 160 GHz for offset frequencies in the ra nge 10 kHz to 10 MHz. At small offset frequencies, the measured phase noise is typically 15 dB higher than solid state oscillators at this f requency.