Patent ID: 8111781
Filing Date: 2012-02-07
Classification: G06K

Abstract:
1. A radio frequency identification (RFID) interrogator, comprising: a signal processing module, for generating an input signal according to a transmission signal transmitted from an RFID tag; a first matched filter, coupled to the signal processing module, for generating a first matched signal according to the input signal and a first predetermined signal pattern; a second matched filter, coupled to the signal processing module, for generating a second matched signal according to the input signal and a second predetermined signal pattern; a control unit, for generating a control signal according to the input signal; and a decision unit, coupled to the first matched filter, the second matched filter and the control unit, for comparing the first matched signal with the second matched signal according to the control signal to generate a read-back signal; wherein the signal processing module comprises: an analog-to-digital converter (ADC), for converting the transmission signal into a digital signal; and a demodulator, coupled to the ADC, for demodulating the digital signal to a Miller basis signal as the input signal, wherein the demodulator comprises: a sub-carrier generator, for generating a sub-carrier signal corresponding to the transmission signal; and a signal comparator, coupled to the sub-carrier generator, for comparing the digital signal with the sub-carrier signal so as to generate the Miller basis signal.