DEMODULATOR FOR DEMODULATING AMPLITUDE SHIFT KEYING-RADIO FREQUENCY SIGNAL AND READER SYSTEM HAVING THE SAME

摘要

An ASK RF demodulator and a reader system comprising the same are provided to clip an ASK RF signal received from an RF tag with a desired signal range, by using a demodulator comprising a clipping circuit implemented with a PMOS transistor. A control voltage generator(110) generates a control voltage in response to an N bit control signal. A clipping circuit(120) generates a clipped signal by clipping an ASK RF(Amplitude Shift Keying Radio Frequency) signal based on the control voltage. A DC remover(130) receives the clipped signal, and removes a DC signal included in the received clipped signal, and generates a signal without a DC signal. A low pass filter block(140) performs low pass filtering by receiving the signal without the DC signal. A variable gain amplifier(150) amplifies an output signal of the low pass filter block on the basis of a gain control signal. A comparator(160) generates a digital modulation signal by comparing an output signal of the variable gain amplifier with a first reference voltage.