IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Dedicated Q factor formulas stemming from oscillation frequency stability against source and load deviations
Takashi Ohira
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2012 Volume 9 Issue 7 Pages 616-621


This paper derives two kinds of Q factor formulas for use in estimating frequency stability of sinusoidal oscillators. To cover various circuit topologies, we consider a general black-box model having DC input and RF output ports. Assuming a small deviation in DC supply voltage or RF load impedance, the frequency shift caused by such deviation is formulated by a perturbation technique. As a versatile criterion to indicate the tolerance of circuit itself, we introduce oscillator Q against each deviation. Since the theory is described in the linear impedance domain, it gives oscillator designers a clear vista on the stability of practical circuits.

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© 2012 by The Institute of Electronics, Information and Communication Engineers
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