LHM Superstrate for High Directivity Microstrip Antenna

Abstract

High antenna directivity is generally desirable for wireless communication systems, whether terrestrial orbased on satellites. Most of the solutions proposed for improvement of the directivity of microstrip patchantennas were to design array of several antennas. The particular disadvantage of this method comes fromthe feeding of each antenna and also from the coupling between each element. A suitable model to eliminatethese two disadvantages is to use a separate superstrate structure. For this purpose a Left-Handed medium(LHM) superstrate used and presented in this study. Both the reference antenna and proposed antenna aresimulated, fabricated, and tested. The simulation results show good agreement with the measurement results.It is observed that the reference antenna directivity increased by 1.72 dB with the proposed LHM superstrateaccording to the measurement results for 12 GHz operating frequency.