WIRELESS IC DEVICE

摘要

Provided is a wireless IC device wherein the size of a radiation plate and radiation characteristics can be determined irrespective of impedance of the wireless IC chip. The wireless IC device is composed of a wireless IC chip (5) which processes transmission/reception signals; a matching inductance element (20) and a planar electrode (25) formed on the front surface of a feed circuit board (10) composed of a flexible dielectric material; and a loop-like radiation plate (30) formed on the rear surface of the feed circuit board (10). The both end sections (30a, 30b) of the radiation plate (30) are electromagnetically coupled with a resonant circuit which includes an inductance element (L1). The wireless IC chip (5) is operated by a signal received by the radiation plate (30), and a response signal transmitted from the wireless IC chip (5) is radiated to the external from the radiation plate (30).