Analog phase shifter and a method for shifting phase of RF signals

摘要

This invention relates to analog phase shifters, and more particularly, to analog phase shifters for controlling the phase of an RF signal over a wide range of frequencies with nearly linear phase change. An exemplary phase shifter includes a front end high-low pass filter, a back-end high-low pass filter, and an all-pass filter coupled in series between the two high-low pass filters. At least one of the filters is tunable for controlling the phase of an input signal over a wide range of frequencies. The high-low pass filter comprises low-pass filters as input and output interface for the high-low pass filter to facilitate impedance match for receiving and outputting RF signal.