A Simplified Vector-Sum Phase Shifter Topology With Low Noise Figure and High Voltage Gain

An simplified vector-sum phase shifter (VSPS) topology is proposed in this article. The proposed VSPS topology employs only one 90° coupler to perform as both an I/Q generator and a vector summer. Compared with the literaturally reported VSPS, the proposed VSPS features a simpler topology and improved noise figure (NF) performance. Moreover, active baluns based on the self-calibration technique are employed to provide antiphase signals and improve the gain performance of the VSPS. For demonstration, a 24–30-GHz VSPS based on the proposed topology is implemented in the 65-nm CMOS process, exhibiting 3.5° rms phase error and 0.9-dB rms gain error. The average gain of the implemented VSPS is as high as 9 dB at the central frequency of 27 GHz. The NF ranges from 4.8 to 9 dB from 24 to 30 GHz, and the core chip size is
$0.36\times0.59$
mm
²
.