Measuring Method of Equivalent Series Capacitance and Negative Resistance of Quartz Crystal Oscillator Circuits,

A measuring method has been developed to obtain the oscillator circuit input impedance characteristics, so that the oscillator circuit operation performance can be estimated without connecting a crystal resonator. The operation performance of the crystal oscillator can be estimated without connecting a crystal unit if we measure how the input impedance, which is usually represented by an equivalent capacitance and a negative resistance, behaves with the frequency and amplitude of the driving signal current of the circuit. In this paper a measuring method of the equivalent capacitance and the negative resistance of the oscillator circuit has been considered. The equivalent capacitance and the negative resistance are measured by comparing them with a reference capacitance and a reference resistance, respectively.