Abstract
A planar ferrite phase shifter is designed to exhibit simultaneous analog and digital phase tuning properties. Analog phase control is achieved by using an external magnetizing field, and digital phase change is realized by switching the phase shifter operation from microstrip to waveguide mode. Simulated and experimental results are presented to demonstrate the impedance matching and dual-phase tuning properties. At 9-GHz, a differential digital phase shift of 100$^{\circ}/$ bit and an analog phase control of 16 $^{\circ}/$mT is exhibited. When applied in phased array antennas, these easily integrated low-cost planar phase shifters can produce high-resolution wide-angle beam scan by employing analog/digital phase control circuits.