Tunable rejection filters with ultra-wideband using zeroth shear mode plate wave resonators

This paper reports wide band rejection filters and tunable rejection filters using ultra-wideband zeroth shear mode (SH 0 ) plate wave resonators. The frequency range covers the digital TV band in Japan that runs from 470 to 710 MHz. This range has been chosen to meet the TV white space cognitive radio requirements of rejection filters. Wide rejection bands were obtained using several resonators with different frequencies. Tunable rejection filters were demonstrated using Si diodes connected to the band rejection filters. Wide tunable ranges as high as 31% were measured by applying a DC voltage to the Si diodes.