Piezoelectric resonators including mass loading to attenuate spurious modes

Claim 1

A piezoelectric resonator with attenuated spurious response comprising: a. a piezoelectric crystal plate having two major surfaces and a surrounding edge; b. an electrode fixedly positioned in overlying relationship on each of said major surfaces, said electrodes being approximately coextensive and directly opposite and providing a main frequency mode of operation and spurious modes upon proper energization thereof; c. an electrically conducting tab fixedly positioned in overlying relationship on each of said major surfaces and extending from electrical connection with said electrode on each respective major surface outwardly to the surrounding edge of the major surface, said conducting tabs extending outwardly to the surrounding edge in different directions so substantially no portions thereof are directly opposite each other; d. a pseudo tabe positioned in overlying relationship on each of said major surfaces approximately coextensive with and directly opposite each of said conducting tabs, said pseudo tabs being spaced from said electrodes a distance sufficient to allow propagation of the spurious modes between said conducting tabs and said pseudo tabs toward the outer edge of said plate while decoupling substantial propagation of the main mode.