| 摘要 |
PURPOSE:To improve input VSWR, by providing a matching element, where a step type waveguide and an iris are combined, in the feeding entrance of a horn antenna. CONSTITUTION:A matching element is constituted by combining step type round waveguide 10 having a diameter larger than the inside diameter of feeding round waveguide 2 and round itid 11. The maximm length length of step type waveguide 10 is set to a length 1.5 or less times as long as 1/4 of the guide wavelength for transmission through waveguide 10 in the TE11 mode in the center frequency so that the input admittance at the view from end face 8 of waveguide 2 may show an inductive susceptance approximately. Iris 11 of a prescribed thickness is provided between waveguide 2 and waveguide 10, and the inside diameter is selected pro perly, so that input VSWR can be improved. |
