An 8-element 400 GHz phased-array in 45 nm CMOS SOI

This paper presents an RF-beamforming phased-array with operation at 375-405 GHz. The phased-array is built using 45 nm CMOS SOI and is based on quadruplers at each antenna element which convert the RF signal from 95-105 GHz to 360-420 GHz. The antennas are high efficiency microstrip design with > 44% radiation efficiency (including the CMOS metal fill) due to the use of a 100 μm-thick quartz superstrate layer. The 8-element linear array scans over +/- 35° of angular space, and results in a peak EIRP of 5 dBm and a 3-dB bandwidth of 375- 405 GHz (EIRP > 2 dBm). To our knowledge, this is the first phased-array with scanned patterns at > 300 GHz using CMOS.