Measurement of oscillator spillover noise in a single sideband system

摘要

A method for measuring oscillator spillover noise produced by a single sideband microwave radio is provided. A white noise signal filtered by a narrow notch filter having a bandwidth on the order of the spillover bandwidth is applied as a modulating input. The white noise signal filtered by wide notch filter is also applied as a modulating input. After demodulation, noise measurements are made in the narrow and wide notches. Because the wide notch contains practically no oscillator spillover noise near its center, the noise measured there can be subtracted from that measured in the narrow notch to provide a figure for the oscillator spillover noise. Idle noise can be subtracted from the wide notch noise value to provide a measure of intermodulation distortion.