| 摘要 |
PURPOSE: A direct detecting method of an RFID card through a comparator is provided to control power of an RFID card reader by determining the existence of an RFID card around an antenna. CONSTITUTION: An RFID(Radio Frequency ID) card reader includes a controlling unit(102), a wireless transceiving unit(105), a frequency generating unit(103), an impedance match circuit(106), and an antenna(107). The RFID card reader connects a comparator(104) with a connecting unit of the antenna and the impedance match circuit. The controlling unit emits energy of direct frequency through the antenna. [Reference numerals] (101) Power controller; (102) Control unit(MCU); (103) Frequency generator; (104) Comparator; (106) Impedance match circuit; (108) Frequency generator; (109) Transceiving controller(base band); (110) Filter mixer amplifier |
