Advisor(s)

C. Vittoria

Contributor(s)

Nian Sum, Katherine S. Ziemer

Date of Award

2008

Date Accepted

8-20-2008

Degree Grantor

Northeastern University

Degree Level

Ph.D.

Degree Name

Doctor of Philosophy

Department or Academic Unit

College of Engineering. Department of Electrical and Computer Engineering.

Keywords

Electrical engineering, Ferrite

Subject Categories

Telecommunication systems--Technological innovations

Disciplines

Engineering

Abstract

Indium doped BaFe12-xInxO19 was prepared by a modified ceramic technique using In2O3, BaCO3, and Fe2O3 followed by mechanical dispersion. The amount of Indium x was controlled by x = 1.0, 1.5 and 2.0. The powder was screen printed on alumina substrate using a suitable binder and in-plane oriented under a dc magnetic field of 15 kOe. The screen printed films were annealed at different durations to produce dense and thick ferrite materials. Scandium doped BaFe12-xScxO19 were produced by a modified chemical co-precipitation technique. The amount x of Scandium doping was varied by x=0.3, 0.5, 0.8 and 1.0. The size of platelets of BaFe12-xScxO19 was controlled by sintering temperature and time. The screen printed and in-plane oriented films were annealed at different temperatures to produce a dense and thick ferrite films. To meet the industry requirements in telecommunication systems, a new type of ferrite phase shifters should be able to work at Ka-band and higher frequencies. Barium hexaferrite with high anisotropy field (HA) is the candidate for high frequency ferrite phase shifter and we could control HA by doping Scandium and Indium. We designed and fabricated a prototype of microstrip line phase shifter by using BaFe10.5In1.5O19 and it worked at 33 GHz. We compared the data of phase shift with simulation.

Document Type

Dissertation

Rights Holder

Tomokazu Sakai


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