Piezoceramic strip resonators and filters

Abstract

Abstract The miniature strip resonators were firstly described by Onoe and Okazaki in 1975 and by Zumsteg in 1976. They originated as a result of the investigation of the miniature and cheap resonators suitable for clock, colour subcarrier and microcomputer oscillators. Attention was given to the AT-cut strip resonators during the past twelve years. The exact three dimensional analysis and design of the AT-cut coupled-mode miniature strip resonator and monolithic filter were prepared and published by Milsom, Elliot, Terry-Wood and Redwood in 1983 and the simplified version of the analysis and the design of the resonators were presented by Tomase and Dworsky in 1984. The piezoceramic strip resonator is a new type of these resonators which is produced in a large series and used in the telephone sets oscillators at the present time. The strip resonators prepared from PZT type of the piezoceramic are considered in the contribution. The analysis and the results of the measurement of the resonators and the elastically coupled two resonator structures suitable for the frequency range from 1 to 5 MHz are given. Two directions of polarization of the strips are considered by analysis. The first direction is the length of the strip and the second one the width. The computed resonant frequency spectrum, parameters of the electric equivalent circuit and the inter resonators coupling are compared with the measured one.