| 摘要 |
PURPOSE:To improve the aperture efficiency by providing a discontinuous face to a waveguide path, adjusting the length from the discontinuous face of the conductive path to the aperture face so as to adjust the amplitude ratio of two basic and high-order propagation modes and the relation of phase. CONSTITUTION:The antenna consists of metallic plates 5, 5' provided with a slot waveguide 1 and discontinuous face 4. The width A' of the metallic plate 5' is selected as A'<1.5 wavelength and the guide 1 is made coincident with the center axis 6, then the mode existing between the metallic plates 5' is only the basic propagation mode. The basic propagation mode generates a high-order propagation mode from the face 4 and when the distance A of the metallic plates 5 is taken as <=2.5 wavelength, the mode propagated between the metallic plates 5 is the basic propagation mode and the 3rd-order propagation mode. Thus, in selecting the length L of the metallic plate 5 to a length where two modes are shifted by the phase by 180 deg., the two modes are overlapped in opposite phase at the aperture face and the aperture distribution close to uniform distribution is obtained. |
