Reflective-Type Phase Shifters for Multiple-Antenna Transceivers

A 10.5-GHz reflective-type phase shifter (RTPS) using resonant loads with L-match impedance transformation (RLT) is implemented in a 0.25-mum SiGe BiCMOS process. A 2.4-GHz RTPS with RLT loads is also integrated in 0.18-mum CMOS; it employs a negative resistance (NR) technique to reduce the loss by 5.9 dB compared to a conventional design that is also implemented. Several other 2.4-GHz reflective loads are fabricated in 0.18-mum CMOS including a Y-shaped dual RLT (DRLT). A transformation converts it from a Y-shape to a Delta-shape and enables use of the NR technique in an RTPS with DRLT loads, wherein the loss is reduced by 10 dB and the phase shift range is increased to over 360deg.