Graphene patch antenna with lateral edges defined by armchair or zigzag structures and PBG substrate

Abstract

In this work, we study the radiation characteristics of a graphene patch antenna in the terahertz band. Antenna performance is maximized by varying specific sub-components. The first variation is the addition of graphene nanoribbons (armchair and zigzag) on the left and right edges of the graphene patch, in order to evaluate the influence of these structures on a patch antenna. Subsequently, air holes are inserted into the silica substrate in order to reduce surface waves effects and increase bandwidth. GNU Octave and HFSS software were used for the modeling and simulation of the antenna and its variations. The results obtained (return loss, impedance, radiation diagram, gain and current density) were good when the structure was modeled only with silica substrate and the best nanoribbon geometry that contributes to the maximization of the performance of the graphene patch antenna is the zigzag one with return loss of $$-\,17.508$$ dB and $$-\,23.490$$ dB in two resonance bands and gain of 3.7 dB. However, when the periodic substrate was added, the antenna radiation characteristics improved considerably compared to antennas with the silica substrate without air holes, where the best result was obtained with the zigzag structure with return loss of $$-\,42.047$$ dB, but the best gain was obtained by the structure without nanoribbons (8.941 dB).