| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently modulate and amplify a transmission signal with low power consumption by a non-contact card reader. <P>SOLUTION: This non-contact IC card reader is provided with a modulation switching circuit 20a for switching switches S1 and S2 according to the value of the binary signal of transmission data, and configured to modulate a carrier signal by switching the power supply voltage of a transmission amplifier 13 constituted of an amplifier to which a carrier signal is inputted to any of two voltages(10V and 8V), and to modulate the carrier signal. A C class amplifier can be used as the amplifier 13 for amplifying the carrier signal. Therefore, the merits of the C class amplifier can be obtained. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
