A +3-dBm-EIRP 240-GHz Circular-Polarized Radiator Utilizing a Sub-THz PA in 65-nm CMOS

We present a circular-polarized radiator in a 65-nm CMOS with a measured equivalent isotropically radiated power (EIRP) of +3 dBm at 239.2 GHz. To boost the radiating power, the subterahertz signal generated from a tripler is enhanced by a fundamental driving amplifier before being fed to an on-chip two-array patch antenna for circular-polarized radiation. A W -band voltage-controlled oscillator (VCO) was codesigned with a push-pull driver to optimize the output power and efficiency. Using the frequency-tuning capability of the W -band VCO, the output frequency was precisely tuned to 239.2 GHz, which provided the maximum output power of +0.5 dBm. The fabricated radiator occupies the chip area of 1.44 mm 2 , and it consumes dc power of 272 mW under a 1.2-V supply.