| 摘要 |
PURPOSE:To improve the efficiency of an antenna used in a furnace or the like, by forming a tip opening of a waveguide tapered for forming it into a slit or a grating form vertically to an electric field and jetting an inactive gas for purge from the tip opening. CONSTITUTION:Since the electric field is in parallel with a short side (b) and a magnetic field is in parallel with a long side (c) in the electromagnetic field distribution of the TE10 mode wave in a rectangular waveguide having the long side and the short side and the electric field strength is maximum at the center of the short side, the grating is fitted or a slit opening is provided in the direction at a right angle to the electric field. Further, the cut-off wavelength of the waveguide depends only on the long side (b), the grating is fitted in parallel with the long side or a narrow and long slit having the long side (b) is provided at the center. An inactive gas intake for purge is provided to the waveguide to prevent the growth of adhered material. |
