A LOW VOLTAGE TUNABLE ANALOG PHASE SHIFTER UTILIZING FERROELECTRIC VARACTORS

ABSTRACT

A distributed transmission line phase shifter was implemented by periodically loading a coplanar transmission line using ferroelectric varactors in a shunt configuration. A single dc bias applied to the phase shifter circuit provides a large relative phase shift. A relative phase shift of ∼ 305 degrees was obtained at 20 GHz for a dc bias of only 5 V.

Keywords:

• voltage tunable dielectrics
• ferroelectric varactors
• coplanar waveguide transmission line
• distributed transmission line phase shifter

ACKNOWLEDGMENTS

This research work was funded by Sensors Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, Dayton, OH. The authors are indebted to the late Dr. Rand Biggers who was instrumental in the process development for the BST thin films, using the process controlled PLD system. The authors acknowledge technical support of Mr. Joe Breedlove during the fabrication of the circuits.