| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform automatic gain control most suitable for communication with a radio tag. <P>SOLUTION: An AGC means 6 sets an AGC value of a variable gain amplifier 32 of a reception par 3 to A and measures an amplitude of a reception signal for a prescribed period after a certain time and then changes the AGC value from A to B on the basis of a measured value after the prescribed period. This change is performed at a timing within a continuous period of 12 '0's in a preamble of a response from the radio tag. <P>COPYRIGHT: (C)2009,JPO&INPIT |
