A 6 Bit Vector Sum Phase Shifter With a Decoder Based Control Circuit for X Band Phased Arrays
This letter presents a 6 bit vector sum phase shifter with a novel control circuitry for X band phased arrays using a 0.25 mm SiGe BiCMOS technology. A balanced active balun and highly accurate I/Q network are employed to generate the reference in phase and quadrature vectors. The desired phase is synthesized by modulating and summing the generated reference vectors using current steering VGAs that are controlled by a decoder based control circuit. The phase shifter resulted in a measured RMS phase error between 9.6 11.7 GHz and between 8.2 12 GHz, achieving 6 bit phase resolution. The chip size is 1.87 x 0.88 mm 2, excluding pads. To the best of authors' knowledge, this is the first demonstration of a digitally controlled 6 bit vector sum phase shifter for X band.
IEEE Microwave and Wireless Components Letters