Patent ID: 7932813

Claim:
An apparatus, comprising: a radio frequency identification (RFID) reader that employs synchronized sampling to obtain a modulation signal from an RFID card notwithstanding employment by the RFID card of any of amplitude shift keying (ASK), frequency shift keying (FSK), or phase shift keying (PSK); wherein the RFID reader employs a signal frequency that is employed to generate a magnetic field that causes the RFID card to produce modulation of the magnetic field, wherein the RFID reader employs the signal frequency to attenuate magnetic field contamination from the modulation signal; wherein the modulation signal comprises one or more subharmonics of the magnetic field, wherein the RFID reader employs synchronized sampling at the magnetic field frequency to further attenuate the magnetic field contamination; wherein the modulation signal comprises an identification signal that the RFID reader obtains from the RFID card; wherein the RFID reader comprises a processor, wherein a single path comprises one or more sample and hold circuits for the identification signal to traverse to the processor of the RFID reader to decode the modulation signal in view of the employment by the RFID card of any of ASK, FSK, or PSK; wherein the RFID reader decodes the modulation signal notwithstanding the employment by the RFID card of any of ASK, FSK, or PSK.