Optimization of wire-medium-based shortened horn antenna

Recent experimental studies confirmed previously numerically predicted phenomenon of gain increase of a shortened horn antenna by embedding a wire-medium-based slab. Obtained results (antenna length of 33% of the length of the optimal horn, the gain equal to the gain of the optimal horn within a 2% fractional bandwidth) proved the basic principle. However, it remained unclear how to choose the design parameters in order to obtain an optimal balance between achieved miniaturization ratio and the gain-bandwidth product. This paper reports preliminary results of numerical optimization of antenna parameters. The measurements on prototyped optimized antennas showed increase of the previously reported bandwidths of both a single-wire-based antenna and a double-wire-based antenna by 50%.