Frequency-temperature compensation of piezoelectric resonators by electric DC bias field.

Electromechanical resonators have been widely used in signal processing and frequency control applications. It has been found that the resonant frequency of most resonator devices is highly temperature dependent, as temperature variation leads to materials properties change as well as resonator dimension change, which result in the undesirable shift of the resonance frequency. In this paper, we present a new frequency tuning method in which direct current (DC) bias field is used to control the resonance frequency of the piezoelectric resonator that is subjected to ambient temperature variations. It has been found that, depending on the polarity, the application of a DC bias field can reduce or increase the resonance frequency of the resonator. The experimental results demonstrate that the DC bias field tuning can achieve fairly good temperature compensation within a certain temperature range, and that the mechanical Q factor of the resonator is quite stable under different DC bias fields.