Varactor-Based 360° Differential Phase Shifter Pair

A differential phase shifter pair which is able to supply full 360 degrees phase difference between two output ports is demonstrated. Thanks to the differential pair configuration, the phase shifter element requires much less phase dynamic range compared to conventional phase shifters. The basic phase-tuning unit contains a 50 ohm host microstrip line, with three identical shorted-stub-loaded varactors and two open-ended stubs on its edge. The phase shifter pair is able to produce full 360 degrees phase difference continuously with a maximum insertion loss of 2.3 dB at 5 GHz and 2.5 dB between 4.75 and 5.25 GHz. The good agreement between simulation and measurement suggests that the differential phase shifter pair is promising and practical for microwave and antenna applications.

Automated summary

A differential phase shifter pair is demonstrated to provide a full 360 degrees phase difference between two output ports. With the differential pair configuration, it requires less phase dynamic range compared to conventional phase shifters. The phase shifter pair is able to continuously produce a full 360 degrees phase difference with good agreement between simulation and measurement, showing promise and practicality for microwave and antenna applications.