| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent inclusion of null area in an acquired communication result due to occurrence of erroneous selection of demodulation output. <P>SOLUTION: A Vb voltage output part 114 outputs a Vb voltage. The Vb voltage is such a value that demodulation output by an ASK demodulating circuit 107 does not become null when a voltage applied to a resistor 105 connected in series with a transmitting and receiving antenna 102 is lower than the Vb voltage, and that the demodulation output by the ASK demodulating circuit 107 becomes null and demodulation output by a Qch demodulating circuit 109 does not become null when the voltage applied to the resistor 105 is higher than the Vb voltage by a predetermined amount. And, a selection circuit selects and outputs the demodulation output by the ASK demodulation part 107 when the voltage applied to the resistor 105 is equivalent to or less than the Vb voltage. <P>COPYRIGHT: (C)2013,JPO&INPIT |
