RESEARCH INTO NEW APPROACHES FOR VHF FILTER CRYSTALS.
Quarterly rept. no. 7, 16 Jan-15 Apr 65,
CLEVITE CORP CLEVELAND OH
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Energy trapping theory was previously applied in the design of 60 Mc, 5th harmonic mode resonator samples. Performance of these units at the 7th harmonic has since been evaluated and represents a substantial improvement for VHF resonators. While energy trapping theory has been principally concerned with responses of the electroded region of a resonator, some insight into the suppression of responses associated with unelectroded region has been gained by considering a simple one-dimensional transmission line model of the resonator. This also interrelates resonator design and filter network design. Experiments observing resonator Qm as a function of electrode length have been conducted in an attempt to correlate with theory involving inter-mode coupling. Results to date have been inconclusive. A method of tuning quartz resonators has been investigated which potentially offers several advantages over conventional tuning techniques. Alignment problems are minimized and an order of magnitude extension of the tuning range should be achievable. Author