Accession Number:

ADA626421

Title:

Non-Reciprocal on Wafer Microwave Devices

Descriptive Note:

Final rept. 25 Jun 2010-24 Feb 2015

Corporate Author:

COLORADO UNIV AT COLORADO SPRINGS

Personal Author(s):

Report Date:

2015-05-27

Pagination or Media Count:

9.0

Abstract:

We studied the growth, structural and magnetic properties of the hexagonal ferrite BaAlxFe12-xO19 films on a surface of Pt templateSi 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 x0 and x2 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 GHzkOe. Experimentally, high signal attenuation 33 67 dBcm 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.

Subject Categories:

  • Physical Chemistry
  • Electrical and Electronic Equipment
  • Solid State Physics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE