300-GHz Dual-Beam Frequency-Selective On-Chip Antenna for High T_c Superconducting Receivers

This paper presents a novel terahertz (THz) on-chip antenna design for highT -c superconducting (HTS) heterodyne receiver frontends. The antenna includes a two-element ring-slot array in conjunction with a hemispherical lens, which generates highly-directional dual radiation beams with stable angular separation, thus significantly facilitating the quasi-optics design for coupling radio-frequency (RF) and local oscillator (LO) THz signals. Besides, a double-layered band-pass frequency selective surface (FSS) is designed, and integrated in the THz on-chip antenna to filter out external interferences other than 300-GHz band for maximizing the HTS receiver frontend's noise performance. Numerical simulation shows that the antenna achieves a coupling efficiency of -3.5 dB and a realized gain of 13.5 dB at 300 GHz, and exhibits very stable radiation performance over the whole operating bandwidth of 283 to 316 GHz.