COMMUNICATION SYSTEM, READER/WRITER APPARATUS AND RF-ID TAG

摘要

When receiving an ASK modulated wave from an R/W apparatus (1) during downstream communication, an RF-ID tag (2) generates a clock from the ASK modulated wave, and demodulates, in synchronism with the clock, the data addressed to the RF-ID tag (2). When receiving, during upstream communication, a modulated wave in which the RF band carrier has been modulated by a periodic waveform signal, the RF-ID tag (2) generates a clock from the modulated wave, and modulates, in synchronism with the clock, and transmits the data addressed to the R/W apparatus (1). In this way, the RF-ID tag (2) can generates, without using any frequency divider that frequency divides the RF band carrier to generate a clock, the clocks and transmit the data to the R/W apparatus (1).