Full H-band waveguide-to-coupled microstrip transition using dipole antenna with directors

In this paper, we propose low-loss and broadband terahertz (THz) waveguide-to-coupled microstrip transitions using dipole antenna with directors. The simulation and measurement show that insertion/return loss and bandwidth of the waveguide transition can be improved by adding two directors to the basic dipole antenna. The fabricated transition with two directors on a 50 µm-thick quartz substrate exhibits a back-to-back insertion loss of 1.5 dB and return loss better than 15.0 dB across full H-band (220–325 GHz). This belongs to the excellent performance compared with the reported H-band waveguide transitions using dipole antenna.