Compact Triple-band Metamaterial Antenna

This paper presents a compact triple-band metamaterial antenna. The presented antenna includes a rectangular radiation patch, a partial ground structure, a staircase microstrip feed line, and two compact loaded metamaterial elements. The triple-band performance obtains with a conventional patch radiator for 3–3.75GHz (22.2%), an interdigital meander slit at the right-side of rectangular patch for 5–5.56GHz (10.6%), and a virtual grounded meander stub at the left side of patch radiator for 6.8–8.3GHz (19.9%) which cover WiMAX, WLAN, LTE, C- and X-band applications. The rectangular defected ground structure and stepped impedance feed line improve the input matching characteristics at all frequency bands. Furthermore, to achieve a better understanding of the presented triple-band metamaterial antenna behavior, key parameters study and equivalent circuit model are used. The proposed via-less metamaterial antenna has a simple design, compact size of 12mmx17.2mm, multiband performances with independently tuning, quasi-omnidirectional radiation characteristics, and a high radiation efficiency in all working bands.