A Metamaterial Inspired Compact Miniaturized Triple-band Near Field Resonant Parasitic Antenna for WLAN/WiMAX Applications

This paper presents a metamaterial-inspired triple-band antenna specified for WLAN and WiMAX applications with a compact size of 24mm x 18mm x 1mm (at 2.4 GHz). It consists of a dual-band left-handed metamaterial (LHM) unit surrounded by a G-style monopole antenna. The LHM is first designed and analyzed with equivalent circuits and simulations. A loop antenna based on the LHM unit is designed and simulated to investigate the radiating performance of the LHM unit structure. We also ran simulations for the G-style monopole. Later, the LHM unit is employed as a near-field resonant parasitic (NFRP) element that surrounded by the G-style monopole. A prototype of this antenna is fabricated. Simulations and measurements were carried out and the results match well, identifying good omni-directional radiating performance. Radiation comparisons with the loop antenna and the G-style monopole indicate that due to NFRP, the G-style monopole's pass bands are shifted to lower frequencies to satisfy 2.45 GHz and 5.5 GHz bands requirements, meanwhile the LHM unit structure operates a third pass band of 3.5 GHz. The compact size and good radiation properties of the antenna render it suitable for WLAN/ WiMAX applications.