This article presents a 220–260 GHz fully integrated phased-array wireless transceiver in SiGe:C BiCMOS featuring direct conversion RF beam-forming. The modular design approach enables 2xN phased arrays and multiple input multiple output (MIMO) systems. The transmitter PA with power−combining boosts the effective isotropic radiated power (EIRP) and reduces the need for external lenses. The antenna array in both the TX and RX is composed of four differential double-folded dipole antennas with local backside etching. With 24 dBm TX EIRP, a beamforming link is demonstrated supporting 50 Gbps over 85 cm with no focusing lenses and ±30° of scanning.