| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact, lightweight, and inexpensive antenna for a communication base station whose synchronizing frequency band is wide, and whose gain is high by improving an antenna for a communication base station for transmitting and receiving several giga-Hz radio waves. SOLUTION: A composite antenna element 1 is constituted so that odd- numbered loop antenna elements 1a, 1b, and 1c whose one cyclic electric length is equal to wavelengthλof radio waves for communication can be connected to each other with the linear part shared, and supported in parallel with a ground plate 2. When a standing wave is synchronously generated by the composite antenna element, they are arranged so as to be faced and isolated at points (indicated by×) where a current value is turned into zero, and a helical coil 3c resonating byλ/4 (or a zigzag-shaped conductive pattern resonating byλ/4) is arranged, and the core line of a coaxial cable 4 is connected to this helical coil 3c.
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