Non-Reciprocal on Wafer Microwave Devices
Abstract
We studied the growth, structural and magnetic properties of the hexagonal ferrite (BaAlxFe12-xO19) films on a surface of Pt template/Si wafer. We determine that our hexagonal ferrite films are highly textured, with the c axis perpendicular to the Si wafer surface and that Al substitution substantially increases uniaxial magnetic anisotropy from 17 to 25 kOe for x=0 and x=2 respectively. This increases in anisotropy field is governed by preferential substitution of Al ions into the 12k, 2a and 2b Fe sites as determined by our Mossbauer spectroscopy studies, consequently reducing magnetization. As a result, the ferromagnetic resonance frequency increases from 35 to 70 GHz in zero applied field. We built a prototype of a fully integrated on-wafer, magnetically tunable band-stop filter on a Si substrate. The filter uses a barium hexagonal ferrite film incorporated into the dielectric layer of a microstrip transmission line. The zero-field operational frequency is about 34 GHz, increasing linearly with the strength of an applied magnetic field at a rate of about 2.7 GHz/kOe. Experimentally, high signal attenuation (33 67 dB/cm) at the resonance frequency and insertion losses as low as 4.5 dB were simultaneously observed, while the 3 dB device bandwidths were below 1 GHz.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 27, 2015
- Accession Number
- ADA626421
Entities
People
- Zbigniew Celinski
Organizations
- University of Colorado, at Colorado Springs