
Accession Number : AD0655776
Title : MICROWAVE RECTIFICATION USING QUARTZ.
Descriptive Note : Physical sciences research papers no. 319,
Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS
Personal Author(s) : Slobodnik,Andrew James , Jr
Report Date : APR 1967
Pagination or Media Count : 70
Abstract : The linear and nonlinear behavior of a thin piezoelectric quartz disk under microwavefrequency excitation is considered both theoretically and experimentally. A theory developed for Xcut quartz predicts the generation of a dc electric field and a corresponding dc voltage across the disk, owing to secondorder coefficients in the piezoelectric constitutive relations. These secondorder coefficients are assumed to be the dominant nonlinearities of the system. Temperature effects are neglected. Microwave acoustic resonances corresponding to high harmonics of the fundamental elastic standing wave were observed for Xcut and ACcut quartz disks, in excellent agreement with the linear theory. Equivalentcircuit methods for description and measurement of these resonances are given. An equivalent circuit describing the nonlinear dc behavior of the disk derived for a simple model. This circuit consists of a voltage source in series with a capacitance. The opencircuit voltage is a product of the secondorder coefficients and the square of the magnitude of the applied electric displacement field, and is in addition dependent on the applied microwave frequency. With a simple model used for the external network, the measurable voltage associated with the effect was determined. Direct comparison of theory and experiment was not possible since the model could not be applied to explain several observed effects. Microwave rectification has been achieved, however, by means of both polished and fineground Xcut quartz disks placed in the gap of a highly reentrant Sband microwave cavity. (Author)
Descriptors : (*RECTIFIERS, QUARTZ), PIEZOELECTRIC CRYSTALS, DISKS, CRYSTAL RECTIFIERS, DRY DISK RECTIFIERS, MICROWAVE FREQUENCY, MICROWAVE EQUIPMENT, THEORY, DEMODULATION
Subject Categories : Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE