A miniature 12 MHz GT cut quartz resonator vibrating in a (m = 3, n = 1) mode

This paper describes a new shape miniature GT cut quartz resonator vibrating at 12 MHz and in a (m = 3, n = 1) mode. A relationship between a dimensional ratio (w/l) and a cutting angle YXlt (θ)/(45°) of the new shape GT cut quartz resonator with first and second order temperature coefficients a = 0 and β= 0 is clarified by FEM (Finite Element Method). Namely, the analysis results show a and β become almost 0, when the dimensional ratio (w/l) is 0.96 and the cutting angle is YXlt (θ = 47°)/(45°). It is confirmed by experiments that the new shape miniature GT cut quartz resonator has a frequency deviation of ±5 ppm in a wide temperature range of -30 °C to +90 °C with a small series resistance R1 of 98 Ω and a quality factor Q of 58000.