RIDGE WAVEGUIDE CENTER FEED SLOT ARRAY ANTENNA

PROBLEM TO BE SOLVED: To provide a center feed offset array antenna such that slot arrays of offset arrays of radiation waveguides on both sides of a feed waveguide are symmetrical across the feed waveguide and the width of the feed waveguide is narrow. SOLUTION: A ridge along a tube axis is provided at a center position of the feed waveguide in a bottom width direction. Electrical field vectors on the right and left sides of the ridge are symmetrical in right-left relation because of the ridge. Consequently, the right and left radiation waveguides are fed in in-phase relation. Further, the cutoff frequency of the waveguides decreases since the ridge is provided, so when it is assumed that an in-use frequency does not vary and the cutoff frequency may be the same, the cutoff frequency can be raised by the decrement and the size of the feed waveguide is reducible in size, so that width of the feed waveguide can be made narrower. COPYRIGHT: (C)2008,JPO&INPIT