FILTERING DEVICE FOR ELECTROMAGNETIC WAVE PROPAGATED INSIDE ROTATIONALLY SYMMETRIC WAVEGUIDE PROVIDED WITH INSERTED RECTANGULAR WAVEGUIDE FILTER SECTION

摘要

PURPOSE: To eliminate the need for providing an element on the inner side of a waveguide by selecting the number of filter sections, a geometrical shape and dimensional characteristics so as to constitute a filter provided with a predetermined filtering profile. ;CONSTITUTION: A circular main waveguide is separated into two parts 41A and 41B, and a rectangular waveguide section 42 is inserted between them. Walls 44A and 44B are almost vertical to a symmetry axis 45 of the main waveguides 41A and 41B, and the walls 44A and 44B are constituted of metal. The circular waveguide 41A is positioned at the center of the rectangular waveguide 42, which is effective in that a cross section 43 in common to the two waveguides is circular. In the case that the polarized waves of a TE₁₁ mode inside the circular waveguide are vertical to the short side surface of the rectangular waveguide section, the TE₁₁ mode is completely passed through in the frequency band of 12-13GHz, and a reflection coefficient is close to 0. Thus, the need for providing the element inside the waveguide is eliminated, and manufacturing is facilitated from a mechanical point of view.;COPYRIGHT: (C)1993,JPO