Design and Improve Coatings for some Antennas

Abstract

In this paper, antireflection coating is designed for helical and loop antennas depending on the variable of refractive indices for microwave region of electromagnetic spectrum by use characteristic matrix method in computer program MATLAB version 7. helical antenna works within the range({3.12-6.66}x108 nm ( it has copper as a substrate . The results shows that, for the normal incidence, the reflectance of copper reduced from (17.38%) to (0.1065%) when coated by two layer MgO and BeO as low and high index coating materials respectively according to the design [Air/LH/Cu]. Also the effect of angle of incidence on the reflectance spectrum of this design are investigate.And loop antenna works within the range({3.48-9.67}x108 nm ( it has zinc as a substrate . The results shows that, for the normal incidence, the reflectance of zinc reduced from (11.11%) to (0.06242%) when coated by the layer SiO2according to the design [Air/L/Zn]. The results shows that the reflectance are increases with shifting toward shorter wavelengths.