Dirac Leaky Wave Antennas

Abstract

Dirac leaky-wave antennas (DLWAs) are derived from photonic crystals exhibiting Dirac cone dispersion around their $\Gamma$-point. DLWAs provide high directive beams and continuous frequency beam scanning, non-fluctuating leakage constant and real non-zero Bloch impedance at and around broadside, due to the closed and linear Dirac dispersion relation around broadside. These features, along with their inherent compatibility for higher frequency designs (larger unit cells compared to metamaterials), make DLWAs an ideal candidate for the upper microwave, mm-wave and terahertz frequencies, and for applications such as radar, 5G, spectroscopy, etc. In this review, we cover the recent developments on Dirac leaky wave antennas, their principles and salient features, and technological potentials of these structures.