Ferrite substrate in patch antennas for millimeter wave applications

This paper aims to study the radiation characteristics of annular ring microstrip antennas printed on a double-layered substrate that is constituted by an isotropic and a ferrite layers. The influence of the applied dc magnetic bias field on the radiation characteristics of these structures is examined. The analysis is performed in the Hankel transform domain using Hertz vector potentials and Galerkin method. Numerical results are presented for the antenna main characteristics such as resonant frequency and radiation pattern.