title: Dirac leaky-wave antennas for continuous beam scanning from photonic crystals.
abstract: Leaky-Wave Antennas (LWAs) enable directive and scannable radiation patterns, which are highly desirable attributes at terahertz, infrared and optical frequencies. However, a LWA is generally incapable of continuous beam scanning through broadside, due to an open stopband in its dispersion characteristic. This issue is yet to be addressed at frequencies beyond microwaves, mainly as existing microwave solutions (for example, transmission line metamaterials) are unavailable at these higher frequencies. Here we report leaky-wave radiation from the interface of a photonic crystal (PC) with a Dirac-type dispersion and air. The resulting Dirac LWA (DLWA) can radiate at broadside, chiefly owing to the closed Γ-point bandgap of the Dirac PC. Thus, the DLWA can continuously scan a directive beam over a wide range of angles by varying the frequency. These DLWAs can be designed at microwave as well as terahertz to optical frequencies, with feasible dimensions and low losses.
authors.affiliation: The Edward S. Rogers Sr Department of Electrical and Computer Engineering, University of Toronto, 40 Saint George Street, 10 King's College Road, Toronto, Ontario, Canada M5S 2E4.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Memarian
authors.affiliation: The Edward S. Rogers Sr Department of Electrical and Computer Engineering, University of Toronto, 40 Saint George Street, 10 King's College Road, Toronto, Ontario, Canada M5S 2E4.
authors.forename: George V
authors.initials: GV
authors.lastname: Eleftheriades