Abstract

In this thesis, the design of a broadside resonant linear array antenna of longitudinal slots on substrate integrated waveguide (SIW) for uniform aperture distribution and for a symmetric tapered distribution is presented. The concept of SIW has been proposed and used in which an "artificial" waveguide is synthesized and constructed with linear arrays of metallized via-holes or posts embedded in the same substrate used for the planar circuit. The SIW has been suitably converted to an equivalent rectangular waveguide. Elliott's modified design procedure including the internal higher order mode coupling, suitable for the usual range of thickness of the substrate, has been followed to obtain the optimum dimensions and positions of slots. The data for 'self-admittance' of an isolated slot as a function of its length and displacement, a requisite in Elliot's design procedure, has been generated by a commercially available full-wave finite element package Ansoft HFSS using an equivalent circuit for the slot with a subsequent extraction of Stegen-type curves. The validity and accuracy of the methodology have been compared with available published results for a slot on an X-band waveguide at 9.375 GHz.