An L-Band SiGe HBT Active Phase Shifter Based on Two-Stage Amplifier Designs with Resistor-Loaded LPF/HPF-Switching Interstage Networks

Abstract

An L-band 4-bit SiGe HBT active phase shifter is presented. It is based on two-stage amplifier designs with resistor-loaded LPF/HPF-switching interstage networks. A phase shifting can be accomplished by varying the value of a bridging resistor and/or a characteristic resistance of the filter. The implemented active phase shifter has achieved a gain greater than 20dB, a gain error less than 1.8dB and a phase error less than 9 degrees at 0.8 GHz for all bits.