full text https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942042976&doi=10.1002%2fmmce.20942&partnerID=40&md5=6d7abe18299e8a63092325c546d3b037
abstract Two planar antennas based on metamaterial unit-cells are designed, fabricated, and tested. The unit-cell configuration consists of H-shaped or T-shaped slits and a grounded spiral. The slits essentially behave as series left-handed capacitance and the spiral as a shunt left-handed inductance. The unit-cell was modeled and optimized using commercial 3D full-wave electromagnetic simulation tools. Both antennas employ two unit-cells, which are constructed on the Rogers RO4003 substrate with thickness of 0.8 mm and ¿r = 3.38. The size of H-shaped and T-shaped unit cell antennas are 0.06¿0 × 0.02¿0 × 0.003¿0 and 0.05¿0 × 0.02¿0 × 0.002¿0, respectively, where ¿0 is the free-space wavelength. The measurements confirm the H-shaped and T-shaped unit-cell antennas operate across 1.2-6.7 GHz and 1.1-6.85 GHz, respectively, for voltage standing wave ratio (VSWR) < 2, which correspond to fractional bandwidth of ~140% and ~ 145%, respectively. The H-shaped unit-cell antenna has gain and efficiency of 2-6.8 dBi and 50-86%, respectively, over its operational range. The T-shaped unit-cell antenna exhibits gain and efficiency of 2-7.1 dBi and 48-91%, respectively. The proposed antennas have specifications applicable for integration in UWB wireless communication systems and microwave portable devices. © 2015 Wiley Periodicals, Inc.
keywords index terms left-handed structures metamaterials planar antennas ultra-wideband antennas bandwidth cells computational electromagnetics cytology metamaterial antennas metamaterials microwave antennas mobile antennas radio transceivers wireless telecommunication systems free-space wavelengths full-wave electromagnetic simulation index terms left handed metamaterial-based antennas planar antennas uwb wireless communications voltage standing-wave ratio ultra-wideband (uwb)