On-Chip Terahertz Topological Filter Antenna for 6G

In this paper, we unveil one of the first demonstrations of an on-chip terahertz (THz) photonic filter antenna for sub-THz communication. Building on the novel physics of photonic topological insulators (PTI), we design an ultra-low loss miniaturized integrable filter antenna. In addition to the low bending and insertion losses characteristic of a PTI system, the inherent photonic crystal (PC) bandgap enables a sharp out-of-band rejection bandpass filter. The propagating edge modes within the passband are radiated efficiently in the end-fire direction with a structure's total efficiency over 90%, a reflection coefficient below -10 dB, and a realized gain of 10.1 dBi. This work accelerates the development of THz photonic integrated circuitry for 6G and beyond.