Metamaterial enhanced high gain antenna for WiMAX application

A high gain low-profile antenna design using metamaterial technology operating at WiMAX 2.5-GHz band (2.50-2.69 GHz) is constructed and measured. A metamaterial superstrate, composed of stacked S-shaped split-ring resonators, can modify the radiation pattern and exhibit gain enhancement functionality. In addition, the proposed structure can be made in economic 4-layer via-less FR-4 printed circuit boards. Therefore applying this technology to commercial applications becomes more practical. With this thin metamaterial superstrate (1.4 mm thick and 10.5 mm above the antenna ground), the patch-based antenna can achieve a maximum gain of 12.2 dBi. The impedance bandwidth of the proposed antenna is about 390 MHz (2.50-2.89-GHz, defined by 2:1 VSWR standard).