Numerical and experimental investigation of horn antenna with embedded ENZ metamaterial lens

Recent numerical study indicated possibility of use of a double thin-wire metamaterial slab as a flat lens that can be embedded into a horn antenna. This led to the construction of the horn, the gain of which is almost equal to the gain of an optimal horn across the moderate bandwidth, but with the substantially shorter length (down to 52% of the original length). Here, we perform both numerical and experimental investigation of such shortened horn antenna operating in 10 GHz band. Simulation showed that both the single thin-wire media and double thin-wire media indeed increase the gain of the shortened horn antenna by 2 dB in 10% fractional bandwidth with return loss better than -13 dB. Qualitatively similar results were obtained for the lens made out of fictitious continuous ENZ material with Drude dispersion model, which indicates that theory of the continuous media can be used for the initial design. Finally, measurements of the gain of experiential antennas verified existence of the phenomenon of gain increase.