Broadband linearly polarized beat-wave TE{sub m1}/TE{sub 11} mode converters
Journal Article
·
· IEEE Transactions on Microwave Theory and Techniques
- Univ. of California, Davis, CA (United States). Dept. of Applied Science
- Innovative Microwave Technology GmbH, Stuttgart (Germany)
- CPI/Varian Associates, Inc., Palo Alto, CA (United States)
Broadband linearly polarized waveguide mode converters have been developed to transform the high-order cylindrical TE{sub m1} output wave from harmonic gyrotron amplifiers into the more useful TE{sub 11} fundamental waveguide mode. The converter`s corrugation period is equal to the beat between the two waves and the bandwidth is predicted to be inversely proportional to the number of periods. Four-period TE{sub 31}/TE{sub 11} and TE{sub 41}/TE{sub 11} converters with an azimuthal perturbation of m{sub c} = 4 and m{sub c} = 5, respectively, have yielded a peak conversion efficiency of 98% with a bandwidth greater than 3% and a one-period beat-wave converter has been designed to yield 12% bandwidth. However, it has been observed in measurements that the strong coupling in a short converter can lead to a shift of the center-frequency with an accompanying reduction of the efficiency and bandwidth. A two-period TE{sub 41}/TE{sub 11} converter with 5% bandwidth displayed a 5% frequency shift and a conversion efficiency of only 86%. This is relevant for electron cyclotron resonance heating (ECRH) at magnetic fusion reactors.
- OSTI ID:
- 218518
- Journal Information:
- IEEE Transactions on Microwave Theory and Techniques, Journal Name: IEEE Transactions on Microwave Theory and Techniques Journal Issue: 2 Vol. 44; ISSN IETMAB; ISSN 0018-9480
- Country of Publication:
- United States
- Language:
- English
Similar Records
Design of Matching Optics Unit (MOU) for coaxial ITER gyrotron
Design improvements for mode and polarization converters for 6-GHz gyrotrons
Optimization of novel high-power millimeter-wave TM{sub 01}-TE{sub 11} mode converters
Conference
·
Fri Jul 01 00:00:00 EDT 2011
·
OSTI ID:22078272
Design improvements for mode and polarization converters for 6-GHz gyrotrons
Thesis/Dissertation
·
Tue Dec 31 23:00:00 EST 1985
·
OSTI ID:5104361
Optimization of novel high-power millimeter-wave TM{sub 01}-TE{sub 11} mode converters
Journal Article
·
Mon Mar 31 23:00:00 EST 1997
· IEEE Transactions on Microwave Theory and Techniques
·
OSTI ID:477336