New type of horn based on variable metasurface

This paper demonstrates the design and the analysis of a novel type of horn antennas with a potentially higher directivity. The idea is to replace one plate of an H-plane horn antenna with a plate that has specially designed surface impedance. In our case we generated the surface impedance variation that corresponds to a Luneburg law, thus obtaining the Luneburg lens effect and consequentially increasing the directivity and reducing the overall horn length.