Accession Number : AD0443951


Title :   FERROELECTRIC CERAMIC FILTERS, IF TRANSFORMERS AND NETWORKS.


Descriptive Note : Final rept. 1 Dec 61-29 Feb 64,


Corporate Author : CLEVITE CORP CLEVELAND OH


Personal Author(s) : Curran, D R ; Gerber, W J ; Koneval, D J ; Waren, A D


Report Date : 27 Apr 1964


Pagination or Media Count : 1


Abstract : The feasibility of applying ceramic Uni-Wafer techniques to quartz was domonstrated, yielding quartz Uni-Wafer filters and networks. The behavior of high frequency quartz resonators has been explained in terms of elastic wave theory and a cut-off phenomenon, where the cutoff frequency for lateral propagation in the wafer is given by its plane wave thickness shear resonance. Because of electrode mass-loading, each resonator area has its resonant frequency below this cut-off frequency and therefore is in effect a trapped energy mode. Vibratory energy excited in the resonator cannot propagate away and therefore is restricted to the electroded region as a standing wave with only an exponentially attenuated fringe extending beyond the electrode. The exponential attenuation in the region beyond the electrode has been confirmed by measurements of mechanical coupling between pairs of resonators and between a resonator and an absorbing edge of the wafer. The predicted standing waves within the electrode region offer a plausible explanation for inharmonic overtone modes observed in high frequency AT-cut quartz resonators, and suggest a design criterion relating electrode dimension with electrode mass loading. (Author)


Descriptors :   *CRYSTAL FILTERS , *TRANSFORMERS , QUARTZ RESONATORS , ATTENUATION , CHEMICAL MILLING , SILVER , GOLD , ALUMINUM , CHROMIUM , PACKAGING , BANDPASS FILTERS


Distribution Statement : APPROVED FOR PUBLIC RELEASE