| 摘要 |
PURPOSE:To simplify and miniaturize the constitution of a responder by providing a modulation demodulation circuit in the responder in a moving body responding to an interrogation unit. CONSTITUTION:An antenna 201 in the responder 2 receives radiowaves which have been radiated from the interrogation unit 1 and they are input-adjusted in an RF input output circuit 211 in a MODEM 210. If the radiated radiowaves are modulated ones, the received radiowaves are supplied to a diode 212 in maximum, and the MODEM 210 operates as a demodulator, whereby demodulation signals are transmitted to a signal processing circuit 204 through a data input output circuit 213. If the radiated radiowaves are not modulated, the signals are amplitude-modulated by identification signals accumulated in a storage element and are returned to the interrogation unit 1 from the antenna 201. Consequently, it is unnecessary to independently provide the demodulator and a modulator, and the constitution of the responder is simplified and miniaturized.
|
