Design for a linear voltage‐controlled 360°‐analog phase shifter

The article presents the design of a linear voltage‐controlled 360° analog phase shifter operating at 2.2 GHz. It is a reflection‐type with a simple and compact structure, using a λ/4‐coupled‐line coupler with the output ports terminated with identical parallel‐tuned varactor‐diode circuits for a full 360°‐phase shift. Formulas are derived for making use of the dimensions of the transmission lines to linearize the phase shift against the control voltage. Simulation and measurement results on the linearity and insertion loss are presented.