New Compact antenna based on simplified CRLH-TL for UWB wireless communication systems

Abstract

This letter presents the experimental results of a novel planar antenna design which is synthesized using simplified composite left/right-handed transmission-line (SCRLH-TL), which is a version of a conventional composite left/right handed-transmission-lines (CRLH-TL), however, with the omission of shunt-inductance in the unit-cell. SCRLH-TL exhibits a right-handed response with nonlinear dispersion properties and a smooth Bloch-impedance distribution. Arranged within the inner slot of the antenna are three smaller rectangular patch radiators. Each patch radiator is embedded with an E-shaped notch, and located in the antenna conductor is a larger E-shaped notch next to the 50-Ω termination. The E-shaped notches constitute SCRLH-TL property. The gap in the slot between the smaller patches and the conductor next to the larger E-shaped notch determines the impedance bandwidth of the antenna. The dimensions of the smaller patches determine the radiation characteristics of the antenna. The antenna is excited using a conductor-backed coplanar waveguide transmission-line. The antenna covers a bandwidth of 7.3 GHz between 0.7 GHz and 8GHz, which corresponds to 167.81%. In this band, the antenna resonates at 4.75 GHz and 7 GHz; the gain and radiation efficiency at these frequencies are 4 dBi—80% and 3.6 dBi—73%, respectively. The antenna's performance was validated through measurement. The antenna has dimensions of 0.0504λ0 × 0.0462λ0 × 0.0018λ0, where λ0 is free-space wavelength at 700 MHz.