Design of a Printed Launcher for Topologically Protected Metawaveguides

Topologically Protected Meta-Waveguides (TPMW) are recently developed structures supporting topological unidirectional modes. In order to excite and receive these modes efficient coupling between TPMWs and conventional structures, like microstrips, is of primary importance. A cross-shaped slot is here proposed to excite circularly polarized modes along an interface between metallic Photonic Crystals (PhC) that behaves indeed as a TPMW. Reflection coefficient lower than -10 dB is observed in a frequency range of 400 MHz for a single port excitation.