Photoconductive bowtie dipole antenna incorporating photonic crystal substrate for Terahertz radiation

In this work, a graphene-based Photoconductive bowtie dipole antenna on a photonic crystal substrate is investigated for Terahertz radiation. Basic graphene radiator involving uniform substrate operates at dual bands of 1.4 THz and 1.9 THz with an efficiency of 80% and directivity of 3.3 dBi. Photonic crystal structure is created by implanting periodic arrangement of cylindrical air holes in the Gallium Arsenide (GaAs) substrate to enhance the performance of the basic antenna design. Due to the suppression of surface wave modes by the photonic crystals, additional resonance is created at 2.1THz, making the antenna to operate at triple bands of 1.4 THz, 1.9 THz and 2.1 THz. Opto-electronic simulation is carried out and emission intensity spectrum is also determined for the first time, in a graphene-based terahertz bowtie dipole antenna involving photonic crystals in it. The directivity of the proposed antenna with photonic crystal is found to be 13.7 dBi, which is 10 dB improvement over the conventional design and efficiency of 95% is achieved.