| 摘要 |
A plate-like radiation element is arranged above a ground plane with a space from the ground plane. The radiation element 2 resonates at a predetermined low-frequency wavelength lambda1 and a predetermined high-frequency wavelength lambda2. A feeding portion for being connected to a feed circuit and a pair of short-circuit portions are provided on peripheral edge portions of the radiation element. The feeding portion is provided on one end of the radiation element. The pair of short-circuit portions for being connected to a ground plane are arranged in areas positioned at opposite sides, on both sides of the feeding portion along peripheral edge directions of the radiation element, where the voltages of high-frequency resonance supplied from the feeding portion to the individual short-circuit portions are zero. The short-circuit portions extend toward the ground plane for being connected to the ground plane. At the other end opposite to the feeding portion of the radiation element is an open end. An electrical length from the one end side to the open end of the radiation element is set to one-half of the high-frequency resonant wavelength lambda2 of the radiation element.
|
