Novel Compact and Low-Loss Phase Shifters With Magnetodielectric Disturber

Magnetodielectric materials show great potential in tunable phase shifter designs with their high relative permeability and high permittivity. This paper presents a novel compact and low-loss tunable S-band phase shifter with a magnetodielectric perturber on a meander line microstrip controlled by a piezoelectric transducer. Compared with traditional dielectric perturbation, the phase tunability of the meander line with magnetodielectric perturber is much larger while the insertion loss is not much affected. Self-biased NiCo-ferrite films were adopted to fabricate the magnetodielectric perturber, which is a ferrite/substrate/ferrite laminate sandwich structure on a commercially available Rogers dielectric substrate. Phase shifter designs with NiCo-ferrite films on one layer to three layers of the sandwich structure were compared and investigated. Relative phase shift of 40° and large phase shift per dB insertion loss of up to 500°/dB were observed at S-band. The proposed S-band phase shifters are compact and will have many potential applications in radars and wireless communication systems.