| 摘要 |
<p>PURPOSE:To receive bit data free from error by synchronizing and detecting a data signal in an IC card which carries out the supply and reception of power and the reception of the data signal at the section of a reader/writer on a noncontact basis. CONSTITUTION:Presently, when the signal consisting of frequencies F is received from a transmitting system 40 of the IC card to a tuning circuit 46 of a transmitting system 43 of the reader/writer, the synchronization to the frequencies F is carried out in the tuning circuit 46, and the signal is sent through a buffer 48 to a mixer 50. In the mixer 50, the frequencies F and a second higher harmonic wave component f2 of the disturbing wave signal are mixed, a basic component f0 and a component f2 are eliminated, and further the signal consisting of only the frequencies F is extracted by a band pass filter 52. Further, for the signal, the detection of the carrier modulated wave corresponding to each bit data, namely, the synchronization detection is carried out by a synchronizing and detecting circuit 54.</p> |
