Patent ID: 8912906

Claim:
An antenna apparatus, comprising: a wireless IC configured to be used in a wireless IC device to perform wireless communication with external equipment and including a first input/output terminal and a second input/output terminal; an antenna resonance circuit including an antenna coil configured to transmit and receive a signal by the wireless communication with the external equipment, one end of the antenna coil being connected to the first input/output terminal, and another end of the antenna coil being connected to the second input/output terminal; and an impedance matching circuit including a portion that is connected between the first and second input/output terminals of the wireless IC and the antenna resonance circuit, the portion of the impedance matching circuit including: a first coil connected between the first input/output terminal and the one end of the antenna coil; and a second coil connected between the second input/output terminal and the another end of the antenna coil, and magnetically coupled to the first coil; wherein the first and second coils are magnetically coupled to each other such that the first and second coils strengthen a magnetic flux with each other.