A 0.4THz Radiating On-chip Locked Source in 65nm CMOS

In this paper a Y-band THz radiating CMOS source in the is presented. The source is based on a differential buffer- less Colpitts D-band VCO, which is tuned by controlling its gate- source capacitance through its transistor drain-gate voltage. The transistor drains are directly coupled to an on-chip loop antenna that chokes the fundamental signal while efficiently radiating the 3rd harmonic generated by the VCO transistor nonlinearity. The source is locked using an external D-band source that radiates the CMOS chip and injection locks the source through its fundamental oscillation. The source can be tuned in a wide frequency range of 405 to 421 GHz with peak total output power of -15dBm (DC to THz radiated power efficiency of 0.1%), EIRP of -6 dBm and DC to EIRP power efficiency of 1.1%. This concept enables simple and cost-effective locked CMOS THz source arrays.