Patent ID: 7382319

Claim:
An antenna structure that comprises a feeding radiation electrode including one end serving as a feeding end and the other end serving as an open end and performing an antenna operation in a plurality of resonant frequency bands and a non-feeding radiation electrode electromagnetically coupled to the feeding radiation electrode and performing an antenna operation in a plurality of resonant frequency bands and said antenna structure being capable of performing radio communication in at least four resonant frequency bands, the lowest fundamental resonant frequency band and a higher-order resonant frequency band higher than the lowest fundamental resonant frequency band among the plurality of resonant frequency bands of the feeding radiation electrode, and the lowest fundamental resonant frequency band and a higher-order resonant frequency band higher than the lowest fundamental resonant frequency band among the plurality of resonant frequency bands of the non-feeding radiation electrode, wherein a main slit is formed in the feeding radiation electrode by a cut in the feeding radiation electrode from an electrode edge of the feeding radiation electrode, wherein one of two sides of the main slit located at an edge of the feeding radiation electrode that are separated by the main slit serves as the feeding end and the other side of the two sides of the main slit located at the edge of the feeding radiation electrode that are separated by the main slit serves as the open end, wherein the feeding radiation electrode has a folded shape and includes a U-turn portion in the middle of a path circumventing the main slit from the feeding end toward the open end, and wherein a sub-slit for forming an open stub that is connected to the U-turn portion and that provides the U-turn portion with electrostatic capacitance is formed, independent of the main slit, in the feeding radiation electrode.