Miniature BAW resonators and filters based on single crystals of strong piezoelectrics

Using single crystals of "strong" piezoelectrics allows sizable reduction of BAW-resonators and filters. This paper reviews new information about development of microminiature BAW-resonators and monolithic filters fabricated from a single piece of quartz, LGS, LGT and lithium tantalate. The investigation results of wideband high-frequency (40-100 MHz) monolithic crystals filters using inverted mesa-technology are given. It is shown that these miniature resonators have considerable smaller values of aging, motional resistance and capacitance ratio in comparison with these parameters of quartz crystal units. The possibility of application of microminiature resonators (volume less than 0.02 cm/sup 3/) of different new types TCXO's, VCXO's, wide-band filters and other devices is proved.