Advanced Artificial Dielectric Materials for Millimeter Wavelength Applications. Part A
Abstract
This is Part A of a two-part Final Technical Report and is restricted to essentially non-magnetic composite dielectrics. Part B, which contains classified material, treats magneto-dielectric composites. We study the electromagnetic properties (permeability and permittivity) of artificial dielectrics with metal particles (1 micrometer to 37 micrometers randomly loaded into both polymeric and inorganic binders. The alloy powder particles are oxide- coated for isolation (non-percolating) and ferromagnetic only below room temperature for volume loading determination, p. Samples with p from 0.1 to 0.4 for various size fractions, were examined from about 1 GHz to 20 GHz, and for selected samples at 35 GHz and 90 GHz. The complex permeability results are in very good agreement with calculations of induced magnetic dipole effects as functions of frequency and particle diameter. Permittivity results (real parts) are independent of particle diameter and essentially constant with frequency. Their dependence on loading is compared to the Clausius-Mossotti dipolar calculation, to the lattice array models with higher-order multipole interactions pioneered by Rayleigh, as well as to a pair-interaction model developed in this study; and also to an empirical curve obtained from several remarkably ideal experiments. The latter two comparisons are rather successful when the particles are closely spherical. We conclude that the microwave electromagnetic behavior of such non-percolating artificial dielectrics is well understood.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 1989
- Accession Number
- ADA220221
Entities
People
- Israel S. Jacobs
Organizations
- General Electric