A Vector Sum Phase Shifter with Active PPF using Transconductance of Transistors

This paper presents a vector sum phase shifter (PS) with an active poly phase filter (PPF) that uses the transconductance of transistors instead of resisters. The accuracy of the PS can be improved by adjusting transconductance of the transistor in the active PPF. The PS, fabricated in 130 nm SiGeBiCMOS process, achieves high gain such as 13 dB, a phase control error of less than 1.1 degree-rms, and an amplitude control error of less than 0.2 dB-rms in 1.7 GHz–3.5 GHz.