CPW-fed electrically small open-ended zeroth order resonating metamaterial antenna with dual-band features for GPS/WiMAX/WLAN applications

Abstract

This paper gives the description of an electrically small (ka = 0.46 < 1) and low profile (0.007 λo) coplanar waveguide (CPW)-fed open-ended zeroth order resonating (ZOR) dual-band metamaterial (MTM) antenna. This MTM antenna is mainly composed of CPW-fed rectangular patch, small square metallic patches, semi-circular patch, and meander line inductor connected to CPW ground plane. The patches form a series inductor, the gap between them refers to the series capacitor, meander line inductor denotes shunt inductor whereas the capacitance between signal line and ground is modeled by shunt capacitor, thus exhibiting composite right/left-handed (CRLH) transmission line (TL). The design produces three resonant bands; first is because of zeroth order mode (n = 0) and the second and third are due to combined effects of coupling between patch and ground plane; and meander line inductor and the ground plane. The measured zeroth-order resonance (ZOR) occurs at 1.22 GHz. The bands due to coupling merge to create a wideband from 4.88 GHz to 7.24 GHz. The radiating unit cell size of the given antenna is 0.07 λo × 0.12 λo × 0.007 λo and the overall size is 0.08 λo × 0.12 λo × 0.007 λo at 1.22 GHz. The measured impedance bandwidths are 3.28% and 38.9% and measured gain is 0.99 dBi and 3.72 dBi for the first and second band respectively. The simulated results are verified through measurement and a good match is found between them. The intended antenna is a good candidature for working in GPS L2 band at 1.22 GHz, WLAN 5.2/5.8 GHz and WiMAX 5.5 GHz wireless applications.