Patent ID: 8098203
Filing Date: 2012-01-17
Classification: H01Q

Abstract:
1. An antenna comprising: a plate-shaped radiation element arranged above a ground plane with a space from the ground plane and arranged to resonate at a predetermined low-frequency wavelength λ a feeding portion connected to a feed circuit and a pair of short-circuit portions connected to the ground plane 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 are positioned in respective portions of a pair of opposed lateral sides, the one end including the feeding portion being positioned between said pair of lateral sides along said peripheral edge portions of the radiation element, where voltages of high-frequency resonance supplied from the feeding portion to individual ones of the pair of short-circuit portions are zero, the pair of short-circuit portions extend toward the ground plane for being connected to the ground plane, the other end opposite to the feeding portion of the radiation element serves as an open end, an electrical length from the one end to the open end of the radiation element is set to one-half of the high-frequency wavelength λ a resonance frequency of the low-frequency wavelength λ a resonance frequency of the high-frequency wavelength λ