STUDY OF ELECTROMAGNETIC PROPERTIES OF CHIRAL MATERIAL

Abstract

The well known phenomena of optical rotation and dichroism may also be observed at micro- and millimeter-wave frequencies provided handed (chiral) microstructures at the appropriate length scales are present in the host medium. In this study, we present experimental results on the Axial Ratio and the material properties μ, c & g (chirality parameter) for chiral material in the frequency range of 8-12.4 GHz. A chiral slab with 2.5% inclusion of miniature metallic springs that are left handed only has been studied. Using spot focussing horn-lens antennas, a linearly polarized plane wave is normally incident to measure both reflection and transmission co-efficients in free space. The computed value of 13 by free space method - the first ever method to directly measure it, is within the theoretical constraint. A new technique involving time domain repines has been used to remove the ambiguity that is encountered in the inversion of measured S-parameters. Besides it, p and c were also found out by conventional waveguide technicue. The results obtained by both the methods are compared.