| 摘要 |
PROBLEM TO BE SOLVED: To suppress a reflection current at the outer peripheral end of an antenna element by connecting the outer peripheral terminal ends of the spiral conductors of spiral elements to the second spiral conductors which are formed to enclose the circumference of whole elements and coating a radio wave absorptive material on the second spiral conductors. SOLUTION: The spiral element 1 is constituted of the two spiral conductors 1a and 1b which are formed on a circular dielectric base board 7 and the spiral element 2 is constituted of the two spiral conductors 2a and 2b which are formed on the base board 7. The four second spiral conductors 3a, 3b, 4a and 4b are formed along the circumference of the board 7 to enclose the whole elements 1 and 2. The conductors 1a and 3a, 1b and 3b, 2a and 4a and the conductors 2b and 4b are connected at the outer peripheral ends of the elements 1 and 2, respectively. A radio wave absorptive material 8 is coated on the second spiral conductors 3a, 3b, 4a and 4b.
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