CAVITY-BACKED SLOT ARRAY FED VIA AN APERTURE IN THICK COMMON BROAD WALL OF A WAYEGUIDE

Abstract

Cavity-backed Slot antennas find, wide applications in the area where miniaturization of the structure and conformability to the surface are the prime requirement of the system. For example, in aircraft and space applications. In this dissertation, moment method analysis of electro-magnetic coupling between waveguide and cavity via an offset slot in the thick common broadwall of the waveguide has been presented. Experimental investigations of electromagnetic coupling between waveguide and cavity, input characteristics including the measurement of S.W.R., input impedance and radiation properties of a single cavity backed slot (CBS) and a five element linear array of cavity backed slots have been performed. A computer program has been written, to implement the analytical procedure for electromagnetic coupling. Offset is shown to control the electromagnetic coupling between waveguide and cavity: Experimental results show that the CBS array has a maximum gain of 9.84 dB in E-plane and a narrow bandwidth (around 2%), while the maximum gain for single CBS was found 4.35 dB in E-Plane.