Robust Leaky-wave Antennas based on Photonic Topological Insulators

In this paper, robust leaky-wave antennas (LWAs) based on photonic topological insulators (PTIs) are investigated. The key condition for the generation of leaky-wave radiation is that the dispersion is located in the fast wave region, and the unidirectional dispersion of topological edge modes just meets this requirement. In this communication, we present design guidelines for a leaky-wave antenna based on Chern-PTIs: First, we design the unit cell of PTIs and perform band topology analysis by the results of the Berry curvature and the Chern number of Chern-PTIs. Second, the special structural design ensures that the bandgaps of the Chern-PTIs and trivial photonic crystals (PhCs) overlap each other, and the two PhCs are stitched together to create a topologically protected waveguide. Finally, we transform the structure in a prototype model and achieve leaky-wave radiation. In addition, the high robustness of the leaky-wave antenna based on Chern-PTIs is also demonstrated in detail.