An 8-Bit 140-GHz Power-DAC Cell for IQ Transmitter Arrays with Antenna Segmentation

An 8-bit power-DAC cell is demonstrated for the first time at D-band in a production 45-nm SOI CMOS technology. The circuit proves the scalability of the transmitter array architecture with antenna segmentation from the W-band to the D-band. The last two stages of the power-DAC cell employ a novel two-stage common-gate Gilbert-cell topology with series-stacking to directly modulate a 125-144 GHz carrier in phase and in amplitude. The measured gain, saturated output power, and PAE of the power- DAC cell are 14.9 dB, 13.2 dBm, and 2.8%, respectively.