Accession Number : AD0476252

Title :   INVESTIGATION OF LARGE SIGNAL MICROWAVE EFFECTS IN FERROELECTRIC MATERIALS.

Descriptive Note : Quarterly rept. no. 5, 1 Jul-30 Sep 64,

Corporate Author : SPERRY MICROWAVE ELECTRONICS CLEARWATER FL

Personal Author(s) : Burdick, G. A. ; Lynn, T. J.

Report Date : JAN 1965

Pagination or Media Count : 40

Abstract : The report includes the derivation and application of a first order correction to the linear approximation of insertion loss versus sample thickness. This correction brings theory and experiment into surprisingly good agreement. A 'flattening' of the dielectric constant versus temperature curve has been noted in the neighborhood of the Curie temperature, suggesting a relaxation is setting in near the Curie point at frequencies around 35 Gc for (Ba-Sr)TiO3 ceramics and BaTiO3 single crystals. In order to check for malfunction of the experimental set-up as a possible explanation of this 'flattening', some additional experiments were performed. The results of these experiments indicate that the 'flattening' is the true behavior of the ferroelectric material. This marks the first time such an effect has been observed for the titanates. The dielectric constant and loss tangent of a newly fabricated batch of (Ba-Sr)TiO3-ceramic were measured for two specimens with consistent results, giving a dielectric constant at room temperature of nominally 800 and a loss tangent of 0.25. (Author)

Descriptors :   (*FERROELECTRIC MATERIALS, MICROWAVES), (*FERROELECTRIC CRYSTALS, MICROWAVES), SINGLE CRYSTALS, CERAMIC MATERIALS, TEMPERATURE, STABILITY, BARIUM COMPOUNDS, STRONTIUM COMPOUNDS, TITANATES, FEASIBILITY STUDIES, LEAD COMPOUNDS, RADIOFREQUENCY POWER, THICKNESS, DIELECTRIC PROPERTIES, DIRECT CURRENT, VOLTAGE, MEASUREMENT, HARMONIC GENERATORS, PARAMETRIC AMPLIFIERS, LIMITERS, MICROWAVE BRIDGES, TEST METHODS, ELECTROMAGNETIC RADIATION, THEORY.

Subject Categories : Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE