Metamaterial-based antennas for integration in UWB transceivers and portable microwave handsets

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 er = 3.38. The size of H-shaped and T-shaped unit cell antennas are 0.06λ0 × 0.02λ0 × 0.003λ0 and 0.05λ0 × 0.02λ0 × 0.002λ0, respectively, where λ0 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. Int J RF and Microwave CAE 26:88-96, 2016.