| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an antenna device acquiring echoes of a large reflector and a small reflector with a difference closer to that between the substantial sizes than in the past. <P>SOLUTION: The aperture distribution at about 2/3 from the aperture center position of a waveguide 11 is set as the Chebyshev distribution of -20 dB, and the aperture distribution at the remaining about 1/3 is set as the Chebyshev distribution of -40 dB. The area where the slot pitch is narrow (a slot 12A to a slot 12E) and the area where the slot pitch is wide (a slot 12E to a slot 12I) are provided, so as to bend the phase convexly toward the top face direction in the middle of the pipe axial direction, and to include a first side lobe in a main lobe. By achieving a narrow beam at 3 dB width and a wide beam at 20 dB width as compared with the Chebyshev distribution, in the antenna device having a similar side lobe ratio, echoes with a difference closer to that between the substantial sizes than in the past is acquired. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
