A New 8 GHz differential 120° Tunable active phase shifter integrated in a $0.25\ \mu \mathrm{m}$ BiCMOS SiGe:C technology

This article presents the design and the implementation of a new architecture of a differential 120° RF active phase shifter, integrated in the QUBiC4X 0.25 μm SiGe:C BiCMOS process of NXP Semiconductors. A new approach with RLC components and differential adders has been used to provide a constant phase shift of 120° at 8 GHz. The power consumption of the proposed phase shifter ( 50 Ω outputs) is 130 mW with a supply voltage of 3 V. The post-layout simulation results show that the circuit has a phase error, around 120°, of less than 3° when the frequency varies from 7.7 GHz to 8.5 GHz. The chip size, including the matching network and the input balun, is 0.5×0.69 mm ² .