A dual-T quartz crystal resonator circuit and its application to 10MHz oscillator

Abstract

In this paper, we have proposed a dual-T quartz crystal resonator circuit of which its resonance frequency can be changed a several thousand ppm exceeding the limit of the piezoelectric coupling factor of a crystal resonator. We have made the measurement of the frequency characteristics of the proposed dual-T circuit composed of 9.995 MHz and 10.005 MHz crystal resonators having the same quality factors. The dual-T circuit showed a single resonant not filter characteristics. And the resonance frequency could be changed about 1000 ppm between the resonance frequencies of the two crystal resonators. We have made an oscillator using the dual-T circuit and measured its performance, too. The variable range about 1000 ppm of the oscillation frequency was observed.