INVESTIGATIONS ON ARTIFICIAL DIELECTRICSAT MICROWAVE FREQUENCIES .PART..... I

Abstract

An expression for the phase change suffered by a H 01 wave in passing through a parallel metallic plate medium for different angles of incidence has been derived from the Carlson and Heins (1947) formula for the transmission coefficient. The shape of the phase change vs. angle of incidence curve obtained experimentally shows fair agreement with the theoretical curve. The difference between theoretical and experimental values of the magnitude of phase shift is considered to be due to diffractioneffects and the presence of higher order modes inside the metallicplate medium. An expression for the phase change on transmission with different spacings of parallel plates has also been derived. Experimental results show that for the size of the dielectric employed, the diffraction effects start when the angle of incidence becomes greater than8°. For normal incidence, the minimum size of the sample of dielectric which is necessary to produce no diffraction effects should be greater than57 x 69 cm.