DocumentCode
1535534
Title
Experimental coupling efficiency of shaping mirrors matching a 168-GHz gyrotron output wave to the HE11 mode
Author
Hirata, Yosuke ; Komuro, Mitsuo ; Mitsunaka, Yoshika ; Hayashi, Kenichi ; Sasaki, Satoshi ; Kanai, Yoshiharu ; Kubo, Shin ; Shimozuma, Takashi ; Sato, Motoyasu ; Takita, Yasuyuki ; Ohkubo, Kunizo ; Watari, Tetsuo
Author_Institution
Toshiba Power & Ind. Syst. Res. & Dev. Center, Kawaski, Japan
Volume
47
Issue
8
fYear
1999
fDate
8/1/1999 12:00:00 AM
Firstpage
1522
Lastpage
1527
Abstract
This paper presents an experiment in which the phase- and amplitude-flattened output of a 168 GHz gyrotron was converted into the HE11 mode, the basic transmitting mode in corrugated waveguides, by means of an external matching box (MBOX) comprising two curved-surface mirrors. In estimating the coupling efficiency between the gyrotron output wave and the HE11 mode, an improved method was proposed in which the reconstructed phase of the gyrotron output wave at four distances are averaged. From the phase reconstruction with averaging, it was found that 76% of the gyrotron output coupled into the HE11 mode in a corrugated waveguide, while a coupling efficiency of 85% was calculated for an ideal gyrotron output. A detailed discussion on the MBOX performance as well as the accuracy of phase reconstruction shows that this low coupling efficiency is due to the nonideality of the actual gyrotron output and that designing the MBOX mirrors based on the actual measurement at the gyrotron window can improve the coupling efficiency
Keywords
gyrotrons; millimetre wave tubes; mirrors; waveguides; 168 GHz; 95 percent; EHF; HE11 mode; MM-wave gyrotron; amplitude-flattened output; corrugated waveguides; coupling efficiency; curved-surface mirrors; external matching box; gyrotron output wave; phase reconstruction; phase-flattened output; shaping mirrors; transmitting mode; Couplings; Cyclotrons; Electrons; Gyrotrons; Heating; Mirrors; Phase estimation; Phase measurement; Power transmission lines; Transmission line measurements;
fLanguage
English
Journal_Title
Microwave Theory and Techniques, IEEE Transactions on
Publisher
ieee
ISSN
0018-9480
Type
jour
DOI
10.1109/22.780404
Filename
780404
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