A 318–342-GHz Microbump-Antenna-Integrated CMOS Transmitter With Spatial Multiplexing for Short-Range OOK Communication

Microbump antenna integrated with active circuits opens the pathway to miniaturized terahertz (THz) short-range communication devices. In this article, a 318–342-GHz spatial multiplexing on-off keying (OOK) CMOS transmitter (TX) with a dual-polarized microbump antenna is presented. First, compared with conventional postprocessing technologies, the solder-ball-based dual-polarized microbump antenna features a low profile, small aperture, and high efficiency. Excellent port isolation and cross-polarization discrimination are achieved. Second, a proposed on-chip switch-based modulator supports Gbps-level data rates above 300 GHz. It maintains constant impedance in <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on/off</small> states at 300–400 GHz. Third, a proposed harmonic oscillator with intercoupling inductors is synthesized based on the two-stage matching network. A high-power THz carrier is provided and less affected by the load variations. The chip is fabricated using a 40-nm CMOS process. The total chip area is 0.3 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, primarily consisting of the aperture. A maximum equivalent isotropic radiated power (EIRP) of −7.1 dBm is achieved at 323 GHz. It provides a 7.2% tuning range, spanning 318–342 GHz. The TX features a recorded switching ratio of 25dB at 323 GHz, and a total efficiency of 0.16% including dc-to-THz efficiency with aperture efficiency. A 2-Gbps data rate at a 5-cm range in a single channel under dual-polarization concurrent communication is demonstrated.