A New 8 Ghz Differential 120 Degrees Tunable Active Phase Shifter Integrated In A 0.25 Mu M Bicmos Sige:C Technology

This article presents the design and the implementation of a new architecture of a differential 120 degrees RF active phase shifter, integrated in the QUBiC4X 0.25 mu m 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 degrees at 8 GHz. The power consumption of the proposed phase shifter (50 Omega 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 degrees, of less than 3 degrees when the frequency varies from 7.7 GHz to 8.5 GHz. The chip size, including the matching network and the input balun, is 0.5x0.69 mm(2).