PURPOSE: To prevent the leakage of a high-frequency wave from the end of a dielectric substance to the outside by covering the edge of the dielectric sub stance fitted to a waveguide for introducing the high-frequency wave or/and the side of the jointed portion of the dielectric substance to the waveguide with a metal film.
CONSTITUTION: A metal film 14 is so formed as to cover the edge 13a of a dielectric substance 13 and the side 13b of the substance 13 where jointed to each of waveguides 11 and 12. An electromagnetic wave transmitted along the waveguide 11 passes the dielectric substance 18 and introduced to the waveguide 12 to be taken outside. In this case, a part of the high-frequency electromagnetic wave when passing the dielectric substance 13, concentrates upon the neighborhood of an edge at the end of a joint with the waveguides 11 and 12. The edge 13a and side 13b of the dielectric substance 13, however, is provided with the metal film 14 and the high-frequency electromagnetic wave concentrating upon the aforesaid neighborhood is diffused over the whole of the film 14, thereby ensuring the prevention of the leakage of the high-frequency electromagnetic wave from the neighborhood of the aforesaid neighborhood.
KAMIMURA KAZUHIRO
HAYASHI KAZUTAKA
ASANO HIROYUKI
