Patent ID: 8917163
Filing Date: 2014-12-23
Classification: G06K,H03G,H04B

Abstract:
1. An active electronic tag, comprising: an antenna, for receiving a detecting signal transmitted from a card reader, wherein the detecting signal is carried on a first carrier; a first amplifier, electrically coupled to the antenna, for amplifying the detecting signal; an automatic gain control circuit, electrically coupled to the first amplifier and utilizing a feedback method to control the first amplifier to stably amplify the detecting signal; a phase synchronization locking circuit, electrically coupled to the first amplifier, and receiving the amplified detecting signal and a transmitting control signal to generate a positive carrier and a negative carrier; a decoding and transmission/reception (TX/RX) control unit, electrically coupled to the first amplifier and the phase synchronization locking circuit, receiving the amplified detecting signal, the positive carrier and the negative carrier, detecting the detecting signal of the first carrier, and generating the transmitting control signal and a response signal according to the detecting signal of the first carrier, wherein the response signal is carried on the negative carrier; and a second amplifier, electrically coupled to the decoding and TX/RX control unit and the antenna, for amplifying the response signal to the antenna and transmitting the response signal to the card reader by the antenna; wherein the response signal utilizes a phase difference between the negative carrier and the first carrier to cancel the first carrier on the card reader, so as to transmit information; wherein the decoding and TX/RX control unit comprises: