A 10-Gb/s, 100-GHz RF Power-DAC Transmitter with On-Die I/Q Driven Antenna Elements and Free-Space Constellation Formation

Abstract

A fully digital mm-wave transmitter with free- space constellation formation above the on-chip antennas is demonstrated at 100 GHz for the first time in a production 45-nm SOI CMOS technology. The transmitter features an RF-DAC architecture with antenna-level segmentation where two DAC elements are driven in quadrature by the external 100-GHz LO signal through an on- chip I/Q hybrid. Each DAC element has 13.9-dBm output power and consists of an on-die differential antenna on quartz superstrate driven by a large power output stage with direct on-off and BPSK modulation. A peak EIRP of 15.7 dBm was measured at 100 GHz with the antenna- limited 3-dB bandwidth extending from 97 to 103 GHz. Data rates of up to 4, 5, and 10 Gb/s were achieved with 9-QAM, BPSK, and QPSK modulation formats, respectively, measured at a distance of 189 mm.