Patent ID: 8472560
Filing Date: 2013-06-25
Classification: G06K,H03D,H04B,H04L

Abstract:
1. An apparatus for detecting an RFID signal in a carrier signal, wherein the carrier frequency is a multiple M of a subcarrier frequency of the RFID signal, the apparatus comprising: a phase detector for generating a clock control signal based on the carrier signal; a pulse generator, the pulse generator configured to provide a predetermined sequence of trigger pulses when triggered by the clock control signal; a plurality of sample and hold units, each of the plurality of sample and hold units comprising a first storage element to store a first value of the RFID signal and a second storage element to store a second value of the RFID signal, wherein the second value is delayed by N cycles of the carrier signal relative to the first value, wherein each of the first and second storage elements are activated according to the predetermined sequence of trigger pulses; and for each of the plurality of sample and hold units, a primary comparator configured to receive the first value and the second value as inputs and output a detected value of the RFID signal for the respective sample and hold unit.