An Overview on the Ceramics Polymers for Microwave Propagation

摘要

Microwave propagation in materials depends on the electromagnetic properties of a medium. The complex permittivity is a represents the ability of a dielectric to absorb electric potential energy. The loss tangent (tanδ) is the ability of the material to convert absorbed energy into heat and hence limited propagation. Ceramics have excellent dielectric, magnetic, thermal and mechanical properties. The brittleness character and high temperature processing of ceramics may lead to the difficulty in manufacturing of complex shapes. Several polymers satisfy the criteria of low relative permittivity (εr) and low tangent loss required for high frequency RF applications. The major problems of the polymers are their high value of the CTE, coefficient of thermal expansion with inferior magnetic properties, tensile strength and thermal conductivity. This review paper will discuss some of the important electrical and mechanical properties of ceramics and polymers wrt to microwave propagation