Measurement of Allan variance and phase noise at fractions of a millihertz

Abstract

Although the measurement of Allan variance of oscillators is well documented, there is a need for a simplified system for finding the degradation of phase noise and Allan variance step‐by‐step through a system. This article describes an instrumentation system for simultaneous measurement of additive phase noise and degradation in Allan variance through a transmitter system. Also included are measurements of a 20‐kW X‐band transmitter showing the effect of adding a pass tube regulator.