A 8-12 GHz Vector-Sum Phase Shifter Using a Marchand Balun and Gilbert-Cell Structure

A full 360° vector-sum phase shifter is presented and demonstrated in this paper. The phase shifter covers the full 360° phase range from 8-12 GHz using 0.45-um GaN technology with a good linearity and high gain. A Marchand balun and a lumped hybrid are implemented for inphase and quadrature phase (I/Q) reference signal and a Gilbert-cell besed VGA is used to add the weighted signals. The simulated rms phase error and rms gain error is less than 3.5°and 2.5 dB. The chip size of the VSPS IC is only 1 × 1.2 mm
²
.