Card read response method, apparatus, and system, and signal transceiving device

A signal transceiving device, comprising:

• an antenna coil with a resonance frequency of 13.56 MHz, an amplification circuit, an analog-to-digital conversion circuit, a first direct current DC blocking circuit, a driving unit, a second DC blocking circuit, a DC power supply and a micro control unit MCU, wherein
• the DC power supply is electrically connected with each of the amplification circuit, the analog-to-digital conversion circuit, the driving unit and the MCU, and configured to supply power to each of the amplification circuit, the analog-to-digital conversion circuit, the driving unit and the MCU;
• the antenna coil is configured to receive a carrier signal with a frequency of 125 KHz;
• the second DC blocking circuit is electrically connected with the antenna coil at a first end of the second DC blocking circuit and electrically connected with an input end of the amplification circuit at a second end of the second DC blocking circuit, and configured to transmit the carrier signal to the amplification circuit;
• the amplification circuit is electrically connected with the second DC blocking circuit at the input end of the amplification circuit, and configured to amplify the carrier signal and output the amplified carrier signal via an output end of the amplification circuit;
• the analog-to-digital conversion circuit is electrically connected with the output end of the amplification circuit at an input end of the analog-to-digital conversion circuit, and configured to perform analog-to-digital conversion on the carrier signal amplified by the amplification circuit to obtain a digital signal, and output the digital signal via an output end of the analog-to-digital conversion circuit;
• the MCU is electrically connected with the output end of the analog-to-digital conversion circuit at a receiving port of the MCU, and configured to acquire, according to the digital signal, a signal characteristic of the carrier signal which comprises at least a frequency and a phase, encode date to be output at the frequency of the carrier signal to obtain an encoded signal, determine an initial phase to output the encoded signal based on the phase of the carrier signal, and output a control signal from a transmitting port of the MCU according to the encoded signal and the initial phase;
• the driving unit is electrically connected with the transmitting port of the MCU at an input end of the driving unit and electrically connected with the first DC blocking circuit at an output end of the driving unit, and configured to output the encoded signal from the output end of the driving unit under control of the control signal;
• and
• the first DC blocking circuit is electrically connected with the output end of the driving unit at a first end of the first DC blocking circuit and electrically connected with the antenna coil at a second end of the first DC blocking circuit, and configured to transmit the encoded signal to the antenna coil.

A signal responding method, comprising:

• receiving a carrier signal with a frequency of 125 KHz via an antenna with a resonance frequency of 13.56 MHz;
• amplifying the carrier signal and performing analog-to-digital conversion on the amplified carrier signal to obtain a digital signal;
• acquiring, according to the digital signal, a signal characteristic of the carrier signal which comprises at least a frequency and a phase;
• and
• encoding response data at the frequency of the carrier signal to obtain an encoded signal, determining an initial phase to output the encoded signal based on the phase of the carrier signal, and outputting the encoded signal via the antenna, such that the encoded signal and the carrier signal are superposed at a same phase.