Accession Number : AD0907396

Title :   VHF Monolithic Filters.

Descriptive Note : Quarterly rept. no. 3, 15 May-15 Sep 72,

Corporate Author : PIEZO TECHNOLOGY INC ORLANDO FL

Personal Author(s) : Smythe, R. C.

Report Date : FEB 1973

Pagination or Media Count : 42

Abstract : This program deals with improvements in VHF monolithic crystal filters in the 100 to 250 MHz frequency range. Efforts will be directed toward minimizing the need for spreading coils and extending the practical number of poles to eight. The value of the maximum inductorless bandwidth, expressed as a percentage of center frequency, depends upon both the resonator capacitance ratio and the magnitude of the stray capacitance present. Special packaging techniques are under investigation to achieve the requirement for low stray capacitance. Experimental work at 111.455 MHz is reported on multi-resonator monolithic and tandem monolithic crystal filters using third overtone plates. Additional four-pole monolithic filters with a 3 dB bandwidth in excess of 40 kHz were successfully fabricated in an HC-18 size envelope. Other techniques are being evaluated for constructing higher-order filters. Intermodulation measurements, using in-band signals, are reported for filters fabricated on the program. Test systems are described and a general review of intermodulation in crystal filters is presented. (Author)

Descriptors :   (*CRYSTAL FILTERS, VERY HIGH FREQUENCY), QUARTZ, COILS, BANDWIDTH, RESONATORS, CAPACITANCE, ACOUSTICS, ENERGY, MODULATION.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE