Coupled mode equations for a high overtone bulk acoustic resonator (a frequency-driving element of high-stability reference generators)

Coupled mode equations for calculating high overtone bulk acoustic resonators (HBARs) are proposed. The calculated and experimentally obtained frequency characteristics of HBARs are compared. The results of implementation of a high-stability generator based on a temperature-controlled HBAR at 754 MHz with a −120-dB/Hz phase noise level and a 1-kHz frequency offset are presented.