ANTENNA AND ANTENNA DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an antenna which does not need a matching circuit with the high frequency stage of a radio circuit by adjusting input-output impedance of the antenna. SOLUTION: This antenna 42 consists of a 1st element 10, where the length from the antenna input-output terminal on a base end side to the front end is equal to the effective length of quarter-wavelength of a prescribed frequency to be resonated and a 2nd element part 12, whose base end is subjected to capacitive coupling to the front end of the part 10 and is arranged with a coupling capacity Cc in a coaxial direction and which also has the effective length of half-wavelength of the prescribed frequency. The input-output impedance of the base end of the part 10 is adjusted to a prescribed value by appropriately setting the capacity Cc.