<title>Experimental verification of grating theory for surface-emitting structures</title>

Abstract

The design procedures for the construction of corrugated waveguides of A1203 and the far field radiation patterns observed from such waveguides is presented. The design procedure is based on the physics of four layer waveguide structures. The corrugated waveguide is similar to a Bragg type diffraction grating. This corrugated structure provides 90° reflections at certain specific wavelengths depending on the grating spacing. A particular advantage of such structures that behave like grating antennas is that their radiation pattern can be scanned electronically by changing the wavelength (frequency). This corresponds to changing the propagation constant of the propagating wave. The far field ra4iation pattern obtained from the experimental set up is compared against simulations carried out using the Huygen -Fresnel theory and a close agreement is seen between theoretical prediction and experimental observation. Specifically, the design and the measurements are made in the frequency range from 90 GHz to 100 GHz for a number of different kinds of structures including those with one as well as multiple sections of corrugations.