A low profile quartz crystal resonator for OXCO in cellular telephone system

We realized 15 mm-in-height quartz crystal resonator with aging characteristic of less than 2/spl times/10/sup -11//day and acceleration sensitivity of less than 1/spl times/10/sup -9//g. Large effort has been paid to the designing of the base structure. We designed the base as low as possible and at the same time, it should avoid the strain transmitting to the quartz plate caused by the coldweld sealing. The mounting angle was experimentally determined so that the acceleration sensitivity would be minimized. As a result, 4.5 mm-in-height quartz crystal resonator with excellent aging characteristic and small acceleration sensitivity was successfully realized.