Improvement of frequency drift of at-cut resonators using an unelectroded resonant region

We propose a new type quartz resonator using an unelectroded resonant region. In this resonator unelectroded resonant regions and electroded resonant regions are acoustically coupled to each other. We examined a transmission type structure resonator using a lumped constant equivalent circuit and confirmed its performance by experiments. The resonance frequency drift observed through electric terminals was improved by one-tenth of the drift at the electroded resonant regions. The insertion loss of the resonator is typically 15 dB, and therefore steady oscillation can be sustained using an ordinary single stage amplifier.