Advanced phase detection technique for the real time measurement and reduction of noise in components and oscillators

A real time noise measurement technique has been developed which allows phase and amplitude noise measurements to be made with much higher sensitivity than previously possible. The technique is applicable at arbitrary operating frequency and can be used to measure the performance of wideband devices. The measurement system is based on an interferometer and a microwave implementation has been developed at X-band; using both connectorised 'mechanical' components and a microstrip module. This paper reports the results of the microstrip implementation as both a noise measurement system and as part of a frequency discriminator in ultra-low noise oscillators.