Accession Number : ADP007738

Title :   In SITU Measurement of the Dielectric Properties of Ceramics with a Single Mode Microwave Heating Device,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK

Personal Author(s) : Yu, X. D. ; Varadan, V. V. ; Varadan, V. K. ; Ghodgaonkar, D.

Report Date : 27 APR 1992

Pagination or Media Count : 9

Abstract : A single mode microwave heating device which operates at 2.45 GHz was modified to simultaneously heat and characterize ceramic materials. The equivalent circuit derived by Marcuvitz 9 to model the ceramic rod in the waveguide was used in the formulation. Three crystal detectors on the impedance analyzer were used as a reflectometer to measure the reflection coefficient of the load, so that transmission line measurements can be automated. The measured reflection coefficient at different temperature is a function of the dielectric constant and loss tangent of the ceramic material. The Newton-Raphson method was successfully used to solve a nonlinear complex equation. By using this system, a 94% alumina rod was heated and characterized and experimental results are presented.

Descriptors :   *CERAMIC MATERIALS, *MICROWAVES, ANALYZERS, CIRCUITS, COEFFICIENTS, CONSTANTS, CRYSTAL DETECTORS, CRYSTALS, DETECTORS, DIELECTRICS, EQUIVALENT CIRCUITS, FORMULATIONS, HEATING, IMPEDANCE, MATERIALS, MEASUREMENT, MODELS, NUMERICAL METHODS AND PROCEDURES, REFLECTION, REFLECTOMETERS, RODS, TANGENTS, TEMPERATURE, TRANSMISSION LINES, WAVEGUIDES, SYMPOSIA.

Subject Categories : Ceramics, Refractories and Glass
      Radiofrequency Wave Propagation
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE