Evaluation of passive component short-term stability via use in low loop delay oscillators

Abstract

Measurement of the PM noise generated by passive components operated at HF carrier frequencies was reported by NIST at the 1998 Frequency Control Symposium [l]. The results were obtained using a two channel, cross-correlation measurement system. The results indicated that the flicker portion of short-term reactance fluctuations of inductors, capacitors, and varactor diodes could result in carrier signal spectral degradation, especially when the components were used in moderate and narrow bandwidth tuned circuits (i.e., bandpass filters.In this paper, the results of similar measurements made in the VHF range are reported. Determination of the short-term reactance stability of several types of inductors, capacitors, varactor and PIN diode-based attenuators and helical resonators has been made. The measurements were made by using these components in simple tuned circuits and multipole filters that are used as the frequencydetermining element in low loop delay oscillators. Using this method, the near-canier phase noise of the oscillator signal is poor enough as to be easily measured. Further, if the oscillator loop delay is known,