WIRELESS IC DEVICE

摘要

A wireless IC device is obtained in which a frequency characteristic and impedance can be determined without depending on an antenna, and whose production is facilitated. A wireless IC device having a flexible sheet (10) provided with a wireless IC chip (5) and radiation plates (11). The wireless IC chip (5) is connected by an Au bump (6) to a feeder circuit (15) which is formed on the sheet (10) and which has a predetermined resonant frequency and a predetermined impedance. The feeder circuit (15) includes electrode patterns (15a) and (15b), and the feeder circuit (15) and the radiation plates (11) are capacitively coupled with each other through the sheet (10).