Appendix B: Material Properties

Abstract

Electrical and thermal conductivities, and relative permittivities and permeabilities of common materials encountered in RF and microwave circuits are given in the tables below. Electrical conductivity is the inverse of resistivity, í µí¼Ž = 1∕í µí¼Œ. Where the material parameter is listed as being variable, the physical parameters depend on the formulation of the alloy and typical values are not meaningful. Manufacturers' data sheets for the specific alloys must be consulted. ⊥ indicates the property in the direction perpendicular to the crystal axis. ∕∕ indicates the property in the direction parallel to the crystal axis. The properties of graphite and sapphire depend strongly on crystal orientation. Material data is taken from several sources, including the Standard Reference Data database of the US National Institute of Standards and Technology [1], the CODATA databases of the International Council for Science, Committee on Data for Science and Technology [2], and references [3-5]. Electrical and thermal properties are functions of temperature. Properties at temperatures other than 300 K should be researched. Foundations for Microstrip Circuit Design, Fourth Edition. Terry C. Edwards and Michael B. Steer.