Wide Impedance-Bandwidth and Gain-Bandwidth Terahertz On-Chip Antenna With Chip-Integrated Dielectric Resonator

A wide impedance- and gain-bandwidth terahertz (THz) on-chip antenna with chip-integrated dielectric resonator (CIDR) backed by a ground plane is proposed in this paper. The antenna employs the inherent silicon substrate in CMOS technologies as a rectangular DR, i.e., the CIDR. This CIDR can be seen as a standard dielectric resonator antenna (DRA) or a magnetic-wall cavity with in-phase reflected waves from the ground. A versatile comb-shaped dipole antenna is designed above the silicon CIDR, functioning both as a feeder for the DRA and an independent radiator. With the proper design of the CIDR and the dipole, multiple higher-order DR modes and the cavity mode are simultaneously excited, namely hybrid-DR-cavity modes. The hybrid modes greatly expand the bandwidth and improve the gain. Simulations show that the -10 dB impedance bandwidth and 3-dB gain bandwidths are 50% and 34.5%, while a peak gain of 6.5 dBi is achieved at 305 GHz. For validation, the antenna is fabricated using TSMC 65-nm CMOS technology and tested by dedicated terahertz measurement setups. The fabricated sample shows a peak gain of 8.6 dBi and the maximum radiation efficiency of 44% at 295 GHz. Meanwhile, low cross-polarization levels and stable patterns are also observed. The features of wide bandwidth, high gain, and low profile make the antenna a good candidate in fully-integrated terahertz transceiver systems. To the best of authors’ knowledge, this is the widest fully-integrated on-chip antenna (OCA) working at THz frequencies.