Single Layer Metamaterial Superstrate for Gain Enhancement of A Microstrip Antenna Array

Abstract

This study focuses on creating and analyzing pentagonal microstrip patch antenna arrays with one, two, and three elements for use in the 10 GHz X-band range, utilizing a metamaterial (MTM) superstrate technique. The MTM superstrate, composed of open circular ring cells, is tailored for a 1×2 array with a 10×8 cell arrangement covering an area of 45×36 mm². A 1×3 array has a 14×12 cell configuration spanning 63×54 mm². Positioned beneath the radiating elements and optimized with a quarter-wave transformer for impedance matching, the superstrate significantly enhances antenna performance. The MTM superstrate alters the radiation pattern and increases the gain by approximately 2 dB, demonstrating a gain improvement of around 27% for high-gain applications in the X-band frequency range. For the 1×2 array, the gain increases from 7.52 dB to 9.58 dB, representing a 27.38% improvement, while the input reflection coefficient improves from -48.6 dB to -58.068 dB, reflecting a 19.5% enhancement. Similarly, for the 1×3 array, the gain rises from 9.69 dB to 11.6 dB, showing a 19.73% increase, and the input reflection coefficient improves from -57.46 dB to -60.64 dB, indicating a 5.54% improvement and a good radiation efficiency of about 79.11%. This work involves designing and simulating the proposed antenna arrays using the Computer Simulation Technology (CST) software.