| 摘要 |
<p>PURPOSE: To enhance the reliability of transponder identification by providing an interrogator with a circuit or the like through which a transponder clock signal is taken out from the responsive signal of the transponder. CONSTITUTION: While responding to the question signal from an interrogator, the amplifier 10 of the synchronous circuit of the interrogator amplifies the responsive signal received from a transponder. This signal is sent to a transponder clock fetching circuit 12, a data fetching circuit 14, and to a start detecting circuit 16. The output pulse train of the fetching circuit 12 is sent to a phase comparison circuit 22, and to correct the output reference voltage Vref of a timing reference circuit 24, it is compared with the output of an oscillator (VCO) 26. The output of the VCO 26 is sent to an interrogator cutoff logic circuit 28, and is related to the 'effective code' signal from a microprocessor 18 by a logic circuit 32. Thus, the question signal is corrected to notify that the response has been received, and that the transmission has been stopped.</p> |
