RESEARCH INTO NEW APPROACHES FOR VHF FILTER CRYSTALS.
Abstract
Experiments with rectangular electrodes on 10 Mc AT-cut quartz wafers have verified the dependence, predicted by energy-trapping theory, of fundamental and inharmonic overtone mode frequencies on resonator design parameters. From these, a generalization of the Bechmann criterion on maximum electrode dimensions has been proposed to include crystallographic orientation and the effect of electrode massloading. Feasibility for multi-electrode filter crystals has been demonstrated with the fabrication of two samples with 4 dot-resonators per wafer. Each set of dot-resonators was electrically connected in parallel to form the equivalent of an oversized single resonator, with resultant motional characteristics adding in the predicted fashion. This technique should allow an extension of the range of motional characteristics available in VHF filter crystals and in turn should lead to greater flexibility in filter network synthesis. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 19, 1964
- Accession Number
- AD0600118
Entities
People
- D. J. Koneval
- Damian Curran