Frequency reconfigurable metamaterial resonant antenna

Abstract

New paradigm has been engineered to exhibit reverse electromagnetic properties. Novel composite and micro-structured materials (metamaterials) have been designed to control electromagnetic radiation. Such substances have been called as Left Handed Material (LHM) with simultaneous negative or positive permittivity, permeability and refractive index or mixed positive and negative. This engineered paradigm was be used to implement the proposed antenna. The proposed frequency reconfigurable metamaterial antenna is a coplanar waveguide (CPW)-fed matamaterial antenna using an epsilon negative transmission line. The resonance frequencies are reconfigured and also reconfiguration from narrow to wideband was also implemented. The reflections coefficient, bandwidth and surface current of the designed antenna were studied and analyzed. The antenna configuration consist of a signal patch, coplanar ground planes, microstip lines (switches) for varying or selecting frequencies. The switches connect the signal patch with the coplanar ground plane to realize increase in inductance LL, which is proportional to the length of the patch, where the switch is located. Since it is very difficult to realize large inductance in microstip lines, a coplanar waveguide was used. The shunt capacitor CR, is obtained from the coupling between the signal patch. Reconfigurability functionality was realized with the help of switches (microstrip lines) incorporated into the antenna. The narrow to wideband configuration is realized by selecting various combinations of those switches. A measured radiation efficiency of more than 70% and gain greater than 1dB was obtained for the narrowband configuration. On the other hand, a measured radiation efficiency of more than 80% and gain greater than 1dB was obtained for the wideband configuration. Computer Simulation Technology (CST) microwave studio was employed as the simulation tool and measurement of the result were obtained via Vector network analyser (VNA).