Patent ID: 8643557

Claim:
An antenna apparatus, comprising: a feeding electrode; a loop-shaped radiation electrode in a non-ground region of a substrate to operate at a resonance frequency in a basic mode and a resonance frequency in a higher mode, the feeding electrode having a first end connected to a feeding portion to supply a current of a predetermined frequency, the loop-shaped radiation electrode extending in a state where a base end of the loop-shaped radiation electrode is connected to a second end of the feeding electrode and having an open end facing the second end of the feeding electrode; a capacitance portion to pass a current of the resonance frequency in the higher mode and to block a current of the resonance frequency in the basic mode, the capacitance portion being formed by a gap between the open end of the loop-shaped radiation electrode and the feeding electrode; a first reactance circuit positioned on the loop-shaped radiation electrode and configured to pass a current of the resonance frequency in the basic mode and to block a current of the resonance frequency in the higher mode; and a second reactance circuit positioned on the loop-shaped radiation electrode and configured to pass a current of the resonance frequency in the higher mode, wherein along a path from the base end to the open end, the second reactance circuit is positioned on the loop-shaped electrode closer to the open end than the first reactance circuit, and closer to a position where a maximum current of the resonance frequency in the higher mode is obtained than the first reactance circuit.