Graphene-Based Photoconductive Antenna Structures for Directional Terahertz Emission

Graphene-based photoconductive antenna structures for optically excited terahertz (THz) emission is reported. Initially, a dipole antenna is designed using plasmonic graphene material on GaAs substrate, and its characteristics are found to be better than the previously reported structures. Further, the dipole antenna was improved to a Yagi-Uda-type photoconductive antenna, to obtain a focused radiation pattern. The proposed THz Yagi-Uda antenna is simulated and found to provide a gain of 8.64 dBi and a directivity of 9.57 dBi. Effect of the applied DC bias on the proposed graphene-based dipole and Yagi-Uda photoconductive antennas are also analyzed, and their emission intensities are obtained.