Wave filter comprising piezoelectric wafer electroded to define a plurality of resonant regions independently operable without significant electro-mechanical interaction

Claim 1

A PIEZOELECTRIC CIRCUIT COMPONENT COMPRISING: A RELATIVELY THIN WAFER OF PIEZOELECTRIC MATERIAL HAVING A RELATIVELY SMOOTH SURFACE FINISH; AT LEAST TWO SPACED ELECTRODES POSITIONED ON ONE MAJOR SURFACE OF SAID WAFER, COUNTER ELECTRODE MEANS POSITIONED ON THE OPPOSITE MAJOR SURFACE OF SAID WAFER IN OPPOSITION TO SAID ELECTRODES; SAID ELECTRODES AND COUNTER ELECTRODES MEANS COACTING WITH THE INTERVENING PIEZOELECTRIC MATERIAL TO FORM AT LEAST TWO INDIVIDUAL RESONATORS INDEPENDENTLY VIBRATORY IN A THICKNESS MODE OF VIBRATION; EACH OF SAID RESONATORS HAVING A PREDETERMINED RANGE OF ELECTRO-MECHANICAL ACTION (R) IN WAFER THICKNESSES IN SAID WAFER MATERIAL SURROUNDING ITS ELECTRODE ON SAID ONE MAJOR SURFACE WITHIN WHICH AN ELECTRO-MECHANICAL ACTION IS EXCITED BY THE RESONATOR AND