An effective approach to phase‐noise reduction for microwave sources

Abstract

In this paper, a new method of phase‐noise reduction for microwave sources is proposed. The phase noise is reduced from a microwave signal generator or microwave oscillator without need of high‐Q components. The output of the microwave source is compared with its delayed counterpart using a six‐port comparator. The detected phase‐difference signal is used to make corrections to the original microwave signal in order to reduce its phase variation due to noise effect. A schematic diagram of this approach is provided and its feasibility is tested by analysis and simulation. Analysis shows that the introduction of the six‐port comparator for phase‐noise reduction is very effective; a great amount of phase noise can be removed and the quality of the microwave signal is improved significantly. The implementation of this approach is also discussed. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 36–39, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11119