A Wideband CMOS Linear Digital Phase Rotator

H. Wang and A. Hajimiri

This paper presents a 10-bit wideband Cartesian phase rotator with a novel linear digital VGA implemented in a 0.13um CMOS process. The VGA topology is robust to device modeling uncertainties and PVT variations. The system provides 7.8dB voltage gain with -3dB bandwidth of 7.6GHz. A maximum phase error of 2º has been achieved for a phase shifting range of 360º with 32 phase steps of 11.25º. The capability to compensate for mismatched quadrature inputs is also demonstrated.