Two-Element 81-86 GHz SiGe Transmitter Beamformer for Backhaul Applications

This paper presents the design and characterization of a two-element 81-86 GHz phased-array beamformer in SiGe BiCMOS for backhaul communication applications. Each transmitter path integrates power-amplifier (PA), power detector, variable attenuators, driver amplifier and a 6-bit phase shifter. The TX front-end achieves 24 dB small signal gain, gain bandwidth of 12 GHz, 17 dBm saturated output power and 14 dBm output-referred 1 dB compression point. The phase shifter achieve full 360° phase span with 6-bit phase resolution, 1.9° rms phase error and 0.11 dB rms gain error at 83 GHz. The IC occupies area of 5.1 mm
²
(including pads) and consumes 312 mW per element at P1dB.