CONTACTLESS READER FOR MOBILE INFORMATION COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a contactless reader such as a reader/writer that receives an amplitude-modulated wireless signal from a mobile information communication body such as an IC card and can demodulate the received signal while preventing a received data component due to an upper side band and a lower side band of the received signal from being lost. SOLUTION: A reception means using a loop antenna 4 in the reader/writer of, e.g. a contactless IC card system receives a wireless signal from the IC card, an amplitude difference generating means using a lower side band trap circuit 5 attenuates the amplitude of the lower side band of the received signal to differentiate the amplitude of the upper side band from the amplitude of the lower side band and a demodulation means consisting of a detector 6 or the like demodulates the received signal where the amplitude of the upper side band is differentiated from the amplitude of the lower side band.