This paper describes a single-chip, 70-80 GHz wireless transceiver utilizing a direct mm-wave QPSK modulator. The transceiver was fabricated in a 130 nm SiGe BiCMOS technology and can operate at data rates in excess of 18 Gb/s. The peak gain of the zero-IF receiver is 50 dB, the double sideband noise figure remains below 7 dB, while the 3-dB receive-chain bandwidth extends from DC to over 6 GHz. The differential transmitter achieves a maximum output power of +9 dBm. The total power consumption of the 1.9 mm × 1.1 mm transceiver is 1.2 W from 1.5, 2.5 and 3.3 V power supplies, including the 4 × 20-Gb/s PRBS generator.