International Symposium on Antennas and Propagation
Wave Propagation in General Bi-isotropic Media
Song-Tsuen Peng, Heng-Tung Hsu,
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The wave phenomena associated with the class of bi-isotropic (BI) materials had attracted great interests for over two decades due to their extra medium parameter which gives additional freedom in designing various microwave devices . Promising applications in antennas including the polarization rotating lenses and the compact microstrip antennas as well as microwave devices and radar engineering are all based on BI materials [1,2]. In the past, efforts have been focused on the development of equivalent parameters in order to treat a BI medium as an isotropic one . Finite-Difference Time-Domain (BI-FDTD) technique had been applied for formulation of modelling wave interactions with BI media based on the decomposition of wavefields [3,4]. Additionally, time-domain modelling for electromagnetic wave propagation in BI media based on the Transmission Line Matrix (TLM) approach had also been proposed [5,6]. In this paper, we present a new approach to the propagation of uniform plane wave in BI media. While the case of normal incidence is the main focus in this paper, the same approach can be applied for the oblique incidence case as well. Firstly, we employ the technique of Scalarization to simplify the Maxwell equations in vector form to become a set of scalar ones, and then introduce the concept of perturbation analysis to exhibit the effect of the bi-isotropy on the wave characteristics in general. The method of analysis is based on the development of the dispersion relation of a BI medium, so that the result obtained are cast in a concise form and will appear as an extension of well known ones of isotropic media. In particular, the familiar technique of equivalent circuit is developed to enhance the understanding of the wave phenomena associated with BI media.