Beam Steering Capability Based on Microstrip CRLH Transmission Line

In this paper, an improved version of Leaky Wave (LW) antenna with capability to scan the pattern continuously versus frequency is presented. The LW transmission line is consisting of 10 cells, each cell is made in the form of 8 finger interdigital capacitor and a shorted stub to the ground through a via. The antenna is printed on Taconic TLY5 substrate. The radiation pattern scans from left to right depending on the excitation frequency at input port. Property of leaky wave antenna using transmission line with left hand materials has been studied recently and results are represented in literature [1, 2]. In this paper, we focus on Composite Right Left Hand (CRLH) effects to study the leaky wave antenna. We are able to obtain a pattern that moves from backward to forward as we increase operating frequency. A wide scanning angle from 80 to 50 Degree has been achieved experimentally. The frequency range for the implemented structure is from 1.5 GHz to 3.6 GHz; scanning for backwards occurs from 1.5 GHz to 2.3 GHz, the forward scanning is performed from 2.4 GHz to 3.5 GHz and for 2.3 to 2.4 GHz the pattern oriented almost broadside.