Antenna Gain Enhancement by 2-D Photonic Crystals with the Γ-Point Dirac Cone

A 2-D photonic crystal having the Dirac cone dispersion characteristics at the Gamma-point in the Brillouin zone is proposed for antenna gain enhancement. The photonic crystal is designed to have the accidental degeneracy at the Dirac point frequency of 60.1 GHz with unit cells of the D-4h symmetry. It is shown by full-wave simulations with the 2-D periodic boundary condition that a perfect transmission occurs at the Dirac point frequency for a normal incident wave. It is also shown by full-wave simulation that a photonic crystal with a 16 x 16 unit cells structure illuminated by a waveguide aperture with the dimension of 8.997 mm x 4.5 mm from the plane 5.0 mm (lambda(0)) away from the photonic crystal can enhance the antenna gain by 2.5 dB.