Analysis of endfire tapered slot antennas

A number of endfire tapered slot antennas in Inset Dielectric Guide (IDG) have been analysed, using two theoretical methods. The first is a straightforward approximation based on considering the IDG as an H-guide. The second method utilises a three dimensional Finite-Difference Time-Domain (FDTD) technique. Both the H-guide and FDTD methods are verified by comparison against measured values. Previously, analysis has concentrated solely on long, depth tapered antennas for producing narrow beams. This contribution considers for the first time shorter, broad beam antennas for possible use as elements in phased arrays. The effects of tapering antenna width are also investigated. Theoretical analysis has shown that IDG is particularly suited to antenna applications due to its polarisation properties. In the past, flared antennas using intermediate slot configurations that support two polarisations have not been considered. A number of such antennas are investigated in this paper.