A highly sensitive millimeter wave quasi-optical FM noise measurement system

A highly sensitive, tunable, low-loss quasi-optical millimeter wave FM noise measurement system using a matched, easily tunable quasi-optical cavity in reflection, to act as a carrier suppression filter, is described. This can operate with matched cavity Q's of several hundred thousand with almost zero insertion loss to provide an extremely high discriminator slope at low power levels. The FM noise measurement system can allow direct measurement of phase-locked sources at low input power levels over ultra-wideband frequency ranges.<
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