Accession Number:

ADA137128

Title:

Research on Ferroelectric Materials for Millimeter Wave Application

Descriptive Note:

Final rept. 5 Aug 1981-4 Dec 1982

Corporate Author:

ROCKWELL INTERNATIONAL CORP THOUSAND OAKS CA SCIENCE CENTER

Report Date:

1983-08-01

Pagination or Media Count:

42.0

Abstract:

The largest and highest quality single crystals of the tungsten bronze family ferroelectric compositions of the strontium - barium niobate family reported to date were prepared by Czochralski growth techniques. Low frequency dielectric properties show low loss and high permittivity as expected. Accurate high frequency dielectric measurements for several compositions were made in a waveguide geometry from 30 to 100 GHz and the electric field sensitivity of the microwave refractive index, dndE, was evaluated by a modulation technique in the same waveguide geometry. Although high values of dndE were observed, an unexpectedly high dielectric loss, which does not fit accepted models for dielectric properties, was observed. This fact, coupled with a high sample-to-sample variability, suggests a commonly occurring extrinsic factor such as growth defects or sample impurities as the key element limiting the use of these materials for phase control applications in millimeter wave radar systems. Similar dielectric measurements were made on a variety of ceramic ferroelectrics. In general the losses were substantially higher in these materials.

Subject Categories:

  • Active and Passive Radar Detection and Equipment
  • Crystallography
  • Electricity and Magnetism
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE