[Table of Contents]

Plasma and Fusion Research

Volume 7, 2405037 (2012)

Regular Articles

Quasi-Optical High Purity HE11-Mode Exciter for Oversized Corrugated Waveguide Transmission
Masatsugu SAKAGUCHI, Hiroshi IDEI, Shin KUBO1), Tetsuji SAITO2) and Takashi SHIGEMATSU2)
Kyushu University, Kasuga, Fukuoka 816-8580, Japan
National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
FURUKAWA C&B CO., LTD, Yamato, Kanagawa 242-0018 , Japan
(Received 12 December 2011 / Accepted 13 February 2012 / Published 10 May 2012)


Oversized corrugated waveguide transmissions are used to transmit high power millimeter wave for electron cyclotron heating in ITER. The HE11 mode purity of the waveguide components is a critical issue not only in the high power operation but also in the low power operation to evaluate the components. Conventional single Gaussian beam system causes edge diffraction and excites higher order modes at the waveguide aperture. A proposed HE11-mode exciter uses beam interference between two Gaussian beams interference and serves the high purity HE11 mode without the edge diffraction. The HE11-mode exciter consists of a scalar feed horn antenna, quasi-optical mirrors and a beam splitter (combiner). Phase matched mirrors correct the Gaussian-like beam excited from the horn antenna to pure Gaussian beam. Authors report the experimental study of the exciter.


electron cyclotron heating, transmission line, Gaussian beam, quasi-optical mirror, high power millimeter wave, mode purity

DOI: 10.1585/pfr.7.2405037


  • [1] Gandini et al., Fusion Sci. Technol. 59, 709 (2010).
  • [2] T. Omori et al., Fusion Eng. Des. 86, 951 (2011).
  • [3] J.L. Doane, Infrared Millimeter Waves 13, 123 (1985).
  • [4] H. Idei and M. Sakaguchi, Proceedings of US/Japan/EU RF Heating Technology Workshop, Austin (2011).
  • [5] B.M. Kolundžija et al., WIPL-D Microwave: Circuit and 3D EM Simulation for RF & Microwave Applications (Artech House, 2005).
  • [6] M.A. Shapiro, IEEE Trans. Microwave Theory Tech. 53, 2610 (2005).
  • [7] S. Silver, Microwave Antenna Theory and Design (McGraw-Hill, New York, 1949) p.170.

This paper may be cited as follows:

Masatsugu SAKAGUCHI, Hiroshi IDEI, Shin KUBO, Tetsuji SAITO and Takashi SHIGEMATSU, Plasma Fusion Res. 7, 2405037 (2012).