DocumentCode :
787905
Title :
Magnetic perturbation effects on noise and startup in DC-operating oven magnetrons
Author :
Neculaes, V. Bogdan ; Jones, Michael C. ; Gilgenbach, Ronald M. ; Lau, Y.Y. ; Luginsland, John W. ; Hoff, Brad W. ; White, William M. ; Jordan, N.M. ; Pengvanich, P. ; Hidaka, Y. ; Bosman, Herman L.
Author_Institution :
Dept. of Nucl. Eng. & Radiol. Sci., Univ. of Michigan, Ann Arbor, MI, USA
Volume :
52
Issue :
5
fYear :
2005
fDate :
5/1/2005 12:00:00 AM
Firstpage :
864
Lastpage :
871
Abstract :
Previous experiments demonstrated that imposing an azimuthally varying axial magnetic field, axially asymmetric, in dc-operating oven magnetrons causes rapid mode growth (by magnetic priming) and significant noise reduction. This configuration was previously implemented by adding five perturbing magnets on the upper existing magnet of the magnetron. Experiments reported here add five perturbing magnets on each of the two existing magnets of the magnetron, restoring the axial symmetry of the magnetic field, while maintaining the five-fold azimuthal magnetic field symmetry. Compared with the unperturbed magnetic field case, it has been observed that the noise close to the carrier is reduced by up to 20 dB, while the sidebands are not completely eliminated for medium and high currents. Magnetron start-oscillation currents are somewhat higher for this axially symmetric, azimuthally varying magnetic field as compared to the baseline unperturbed magnetic field.
Keywords :
magnetrons; microwave heating; noise; axially asymmetric magnetic field; azimuthally varying axial magnetic field; dc-operating oven magnetrons; high-power microwaves; magnetic perturbation effects; magnetic priming; magnetron start-oscillation currents; microwave noise; noise reduction; perturbing magnets; unperturbed magnetic field; Electromagnetic heating; Magnetic fields; Magnetic noise; Magnetrons; Magnets; Microwave devices; Microwave ovens; Noise reduction; Radar applications; Spaceborne radar; High-power microwaves; magnetron; microwave noise;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2005.845857
Filename :
1424370
Link To Document :
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