Quasi-Periodic Leaky-Wave Antenna based on Substrate Integrated Waveguide and Liquid Crystal Technologies

Abstract

A quasi-periodic leaky-wave antenna (LWA) based on substrate integrated waveguide (SIW) and liquid crystal (LC) technologies is presented in this paper for single-frequency dynamic beam steering. The antenna works based on the fundamental space harmonic (${n}$=0) in the frequency band from 10.2 GHz to 12.5 GHz. The transversal slots are etched on the top copper plane to achieve radiation in the forward upper region of space. A very thin layer of nematic LC cell is placed underneath the substrate, which is then biased with an external electric field. The dielectric properties of the LC are controlled by the strength of the bias electric field. As a result, the main beam of the antenna pattern is deflected by an angle which depends on the bias voltage. The angular scanning range depends on the dielectric anisotropy of the LC compound and the substrate-toLC thickness ratio. Simulation results based on the ANSYS HFSS commercial software are used in order to numerically verify the design concept.