Study on the Gain Enhancement of Microstrip Patch Antenna Incorporated with Trapezoid-shaped Metamaterial

A kind of novel trapezoid-shaped metamaterial structure design is proposed in this paper to enhance the microstrip patch antenna's gain by loading with the trapezoid-shaped metamaterial as the antenna's superstrate. The transmission and reflection coefficients simulated by HFSS are utilized to retrieve the effective parameters. The calculated results prove that the presented structure has negative effective permittivity and equivalent permeability simultaneously from 7.09 GHz to 7.19 GHz. The gain of microstrip antenna increased from 8.3537 dB to 10.74 dB with good transmission match between the metamaterial overlying strata and the antenna. The 3D polar coordinate figure also indicates clearly that the gain of the antenna is improved significantly with the trapezoid-shaped metamaterial loaded as its superstrate.