GIGAHERTZ RANGE RESONANT DEVICES FOR OSCILLATOR APPLICATIONS USING SHEAR HORIZONTAL ACOUSTIC-WAVES

Although surface transverse waves (STW's) were thought to be very attractive for stable oscillator applications over the last 15 years, not much has been published on STW oscillators with a performance comparable or better than that of the well-established SAW oscillators. The reason for this fact is that, before 1987, designers of SAW oscillators believed that it was impossible to build a good STW resonator. This paper is an attempt to show that STW resonant devices are not only very well suited for stable oscillator applications but have some unique features offering greater design flexibility than their SAW counterparts. Different designs of single and multimode resonators and resonator filters are presented and their properties in respect to applications in stable fundamental mode fixed frequency and voltage controlled oscillators in the range of 750 MHz to 2 GHz are discussed. Characteristics of SAW and STW two-port metal strip resonators using identical designs are compared. Data from frequency trimming on STW resonators, using heavy ion bombardment, are presented.