Abstract
A compact theta-shaped left-handed meta-atom based on an elliptical split ring resonator (ESRR) with a capacitive loaded strip (CLS), is presented in this paper. The elliptical split ring resonator is a changeover of conventional square split ring resonator (SRR). A CLS is introduced in the middle of the ESRR to increase the electrical length and coupling effect. Electromagnetic transmission characteristics of FR-4 and Rogers RO3010 substrate are investigated in a comparative manner for varying values of substrate parameters which are thickness, dielectric constant and dielectric loss tangent. The effective constitutive parameters are retrieved by using the transmission-reflection method. The proposed structure shows a double negative regime from 3.6 to 5.6 GHz (bandwidth of 2 GHz) for FR-4 and from 3.1 to 4.8 GHz (bandwidth of 1.7 GHz) for RO3010 in microwave frequency spectrum. An effective medium ratio (EMR) of 9.27 and 13.36, implies the novelty of the proposed structure. The proposed ESRR is found to reach the lowest resonance frequency while maintaining smallest electrical size, a highly desired property for miniaturization in RF design. Which makes it a prime candidate to reduce RF signal interference of electronic devices, equipment and systems.