Phase noise characteristics of oscillator circuits emphasizing impedance matching

This paper describes improvement of phase noise characteristics of an Fr oscillator. We have examined the configuration of the Fr oscillator, the loaded Q of which is improved by using matching network, and we have predicted the value of the loaded Q. Furthermore, we actually made several configurations of the Fr oscillator and measured the SSB phase noise. We show that the measured loaded Q of the Fr oscillator corresponds to the calculation results well, and that the phase noise characteristics are improved by decreasing the characteristic impedance of the frequency selective circuit. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(10): 34–40, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10355