Session: TH3B

1:20 PM Thursday, May 27, 2010

Room: 206AB
     
Session: TH3B
Ferrite Materials and Devices
Chair:
Steven N. Stitzer, Northrop Grumman ES
Co-Chair:
Spartak Gevorgian, Chalmers University
Abstract:
This session covers new materials work in ferrite and microwave magnetics, as well as device developments for both low and high power levels. Two papers describe developments in the use of nanomaterials in ferrite devices. One uses magnetic nanowires in an edge mode isolator, and one describes the fabrication and use of multiferroic nanoparticles to achieve magnetic tunability. Thermal design aspects are considered in a paper on magnetically rotatable half-wave plates used in high power phase shifters. The advantages of using of segmented deposited magnetic films for toroidal inductors are described. Means of developing high isolation with multiple circulators interconnected by hybrid couplers are described, using combined modeled and measured results.
 
 
TH3B-1
Dual-Band Integrated Self-biased Edge-Mode Isolator based on the Double Ferromagnetic Resonance of a Bistable Nanowire Substrate
1:20 PM-1:40 PM
L. Carignan1, C. Caloz2, D. Ménard1, 1Polytechnique School of Montreal, Montreal, Canada, 2Ecole Polytechnique of Montreal, Montreal, Canada
(1334)
A dual-band integrated self-biased edge-mode isolator based on the double ferromagnetic resonance of a CoFeB ferromagnetic nanowire (FMNW) substrate, controllable by the geometrical and composition parameters of the FMNWs, is presented. The dispersion diagram of the FMNW edge-mode isolator, taking into account the effective permittivity and permeability of the FMNW medium, predicts two frequency bands of operation. These bands are demonstrated experimentally using FMNWs of 40 nm diameter with a lattice constant of 110 nm. In the presented prototype, isolations of 17 dB at 27.3 GHz and 4.4 dB at 31.2 GHz are observed under zero external applied field. The isolation of the second frequency band is increased to 18.3 dB by applying a small DC magnetic field of 0.13 T. The integrability, self-biased, double resonance, millimeter-wave and dispersion engineering properties of the FMNW medium opens up new possibilities for a diversity of magnetic devices and systems.
 
 
TH3B-2
Magnetically Tunable Nanocomposites for Microwave Applications
1:40 PM-2:00 PM
C. Morales1, J. Dewdney1, S. Pal2, K. Stojak2, H. Srikanth2, J. Wang1, T. Weller1, 1Center for Wireless and Microwave Information Systems (WAMI), Tampa, United States, 2Functional Materials Lab (FML), Tampa, United States
(1832)
In this work, tunability of the microwave properties of Magneto-Dielectric Polymer Nanocomposites (MDPNCs) has been demonstrated for the first time. Particularly, permeability, permittivity and loss factor were tuned by an externally applied DC magnetic field with strength achievable by commercial permanent magnets. The considerable tunability, ease of manufacturing, compatibility with multilayer RF laminates and substrate implementation make this material well-suited for use in tunable microwave circuits. Two custom-built microstrip test fixtures using multi-layer substrates were employed to extract the permeability, permittivity and loss tangent of MDPNCs using S-parameter measurements.
 
 
TH3B-3
L-Band High Power Electronically Rotatable Ferrite Half-Wave Plate
2:00 PM-2:20 PM
C. R. Boyd, Jr., W. E. Hord, S. T. Van Dyke, S. J. McKechnie, Microwave Applications Group, Santa Maria, United States
(1047)
This paper describes the design approach and characteristics of an air-cooled ferrite half-wave plate operating in the vicinity of 1.3 GHz. frequency at a peak power level of 65 kW. and an average power level of 6,500 W. Measured data are presented for an engineering model unit with 0.4 dB. maximum insertion loss, capable of switching between any two states in approximately 500 microseconds.
 
 
TH3B-4
Toroid Microinductors Using Segmented Magnetic Cores
2:20 PM-2:40 PM
F. Hettstedt, U. Schürmann, R. Knöchel, E. Quandt, Christian-Albrechts-University, Kiel, Germany
(1077)
A new approach to toroid microinductors with magnetic core is introduced. The core consist of a segmented metal-polymer composite. The investigations aim at fulfilling the demands of small size, high inductance, high operation frequency, and adequate quality factor required for modern mobile communication electronics. A torodial inductor was designed using HFSS and realized in thin-film technology with various core designs to avoid eddy currents and minimize parasitic capacitance. The magnetic core is formed by a segmented multilayer of sputter deposited soft magnetic FeCoBSi, which was deposited in a special way to realize a crossed anisotropy.The terminal impedance Z11 is determined from measured and simulated S11 parameters. Results show the unique properties of the inductors. The simulated and measured parameters are in reasonable agreement.
 
 
TH3B-5
High Isolation Lange-Ferrite Circulators with NF Suppression for Simultaneous Transmit and Receive
2:40 PM-3:00 PM
S. K. Cheung, W. H. Weedon, C. P. Caldwell, Applied Radar, Inc., North Kingstown, United States
(1627)
This paper presents a new type of circulator that consists of three Lange couplers and two ferrite circulators for broadband, high isolation, transmit noise suppression and simultaneous transmit and receive (STAR). The operation principal of the circulator is based on quadrature phase cancellation and combination techniques. Preliminary results show that the isolation between the transmit and receive port is 24 dB in frequency range of 5-12 GHz without optimization and 60 dB isolation with 800 MHz bandwidth with optimization. The NF data at the receive port show significant suppression of transmit noise for Gain-NF product that exceeds 21 dB.
 
 
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