Highly tapered, uniform phased horn based on variable impedance lens effect

This paper demonstrates the properties of an H-plane horn antenna with its characteristics improved using the principle of variable surface impedance. Modifying the surface boundary conditions on one surface of the parallel plate structure is possible by using printed patches of variable size. By doing so, surface impedance profile which corresponds to Luneburg law can be realized. Luneburg lens designed in this way can then be easily implemented inside planar horn antennas to improve their characteristics. The results of this idea are demonstrated using full-wave simulations and show that it is possible to obtain higher horn directivity and significantly reduce the size of the horn within the operational band of the designed Luneburg lens.