| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wireless IC card reader capable of dispensing with a complicated adjustment and improving the wave detection efficiency by realizing a synchronous wave detection without using a carrier reproduction circuit. <P>SOLUTION: This wireless IC card reader 100 has a synchronous wave detection circuit, and it performs a radio communication with a wireless IC card to read a response signal from the wireless IC card. This reader has an oscillation circuit 102 for oscillating a transmission carrier wave signal, a modulation amplifier part 107 for outputting a transmission signal as a modulation signal, a transmission modulation amplifier part 105 for modulating the transmission carrier wave signal based on the modulation signal, and a receiving demodulation part 114 having a DBM (Double Balanced Mixer) 120 as the synchronous wave detection circuit to demodulate a receiving radio signal. The DBM inputs the receiving radio signal and the transmission carrier wave signal from the oscillation circuit. <P>COPYRIGHT: (C)2004,JPO |
