Am (amplitude modulation) demodulation system for rfid reader device

Abstract

An RFID reader device (31), of the type comprising a demodulator (6) for receiving from a RFID tag (11) an AM (Amplitude Modulation) wave (20) having a predetermined frequency (f) and for retrieving, from the AM wave (20), a demodulated output (6a) associated to predetermined positive or negative Amplitudes of said AM wave (20), said demodulated output having a portion with a frequency F. The AM demodulation system comprises at least a second demodulator (26) for receiving the AM wave (20) and retrieving a second demodulated output (26a) associated to Amplitudes opposite to the predetermined positive or negative Amplitudes, said second demodulated output having a portion with said frequency F; the RFID reader includes a block (27) having, in input, the demodulated output (6a) and the second demodulated output (26a) and returning, in output, an enforced demodulated output (30) with a portion with frequency (f1) doubled with respect to said frequency (F).

Dependencies are inferred from the claim text.