Patent ID: 8774712

Claim:
A contactless communication medium comprising: a base made of an insulating material; an antenna coil section including a conductor wound in a planar shape on the base; an inductance adjusting circuit that is connected to a part of the conductor in the antenna coil section, and is placed on the base; a capacitor connected to the antenna coil section; and a communication processing section that is connected to the antenna coil section and the capacitor to perform contactless communication processing, in which the inductance adjusting circuit has a first conductor pattern, a second conductor pattern, and a third conductor pattern connected in parallel such that (i) one end of each of the first conductor pattern and the third conductor pattern are connected at a first connecting point to the antenna coil section, (ii) one end of the second conductor pattern is connected to the first conductor pattern at a second connecting point which is located between ends of the first conductor pattern and by the one end of the first conductor pattern, (iii) another end of each of the first conductor pattern and the second conductor pattern are connected at a third connecting point to the antenna coil section, and (iv) another end of the third conductor pattern is directly connected to the antenna coil section.