Electrically and magnetically tunable phase shifters based on a barium strontium titanate-yttrium iron garnet layered structure

Authors

J. H. Leach, Virginia Commonwealth UniversityFollow
H. Liu, Virginia Commonwealth University
V. Avrutin, Virginia Commonwealth UniversityFollow
E. Rowe, Virginia Commonwealth University
Ü. Özgür, Virginia Commonwealth UniversityFollow
H. Morkoç, Virginia Commonwealth UniversityFollow
Y.-Y. Song, Colorado State University - Fort Collins
M. Wu, Colorado State University - Fort Collins

Document Type

Article

Original Publication Date

2010

Journal/Book/Conference Title

Journal of Applied Physics

Volume

108

Issue

6

DOI of Original Publication

10.1063/1.3486463

Comments

Originally published at http://dx.doi.org/10.1063/1.3486463

Date of Submission

October 2015

Abstract

We report on the tuning of permittivity and permeability of a ferroelectric/ferromagnetic bilayer structure which can be used as a microwavephase shifter with two degrees of tuning freedom. The structure was prepared by the growth of a yttrium iron garnet (YIG) layer on a gadolinium gallium garnet substrate by liquid phase epitaxy, the growth of a barium strontium titanate (BST) layer on the YIG layer through pulsed laser deposition, and then the fabrication of a coplanar waveguide on the top of BST through e-beam evaporation and trilayer liftoff techniques. The phase shifters exhibit a differential phase shift of 38°/cm at 6 GHz through permittivity tuning under an applied electric field of ∼75 kV/cm and a static magnetic field of 1700 Oe. By tuning the permeability through the applied magnetic field we increase the differential phase shift to 52°/cm and simultaneously obtain a better match to the zero applied electric field condition, resulting in an improvement in the return loss from 22.4 to 24.9 dB. Additionally, we demonstrate the use of a lead magnesium niobate-lead titanate (PMN-PT) layer to tune the permeability of the YIG layer. This tuning relies on the piezoelectric and magnetostrictive effects of PMN-PT and YIG, respectively. Tuning of the ferromagnetic response through strain and magnetostriction as opposed to applied magnetic field can potentially pave the way for low power consumption, continuously and rapidly tunable, impedance matched phase shifters.

Rights

Leach, J. H., Liu, H., & Avrutin, V., et al. Electrically and magnetically tunable phase shifters based on a barium strontium titanate-yttrium iron garnet layered structure. Journal of Applied Physics, 108, 064106 (2010). Copyright © 2010 American Institute of Physics.

Is Part Of

VCU Electrical and Computer Engineering Publications