Abstract: An RFID reader is operable to receive an inbound RF signal from an RFID tag during transmission of an outbound RF signal. The inbound RF signal from the RFID tag is a modulated, backscattered signal that includes a desired RF signal component and a blocking RF signal component. The receiver section of the RFID reader includes a preprocessing module operable to process the inbound RF signal. The preprocessing module includes an adjustable attenuation module operable to attenuate the inbound RF signal to produce an attenuated inbound RF signal and an active blocking rejection module operable to increase a ratio of the desired RF signal component to blocking RF signal component in the attenuated inbound RF signal.

Abstract: A receiver architecture for canceling blocking signals in the receive path includes a low noise amplifier for receiving and amplifying an inbound RF signal to produce an amplified inbound signal, in which the inbound RF signal includes a modulated RF signal and a blocking signal, and a cancellation module for substantially canceling the blocking signal from the amplified inbound RF signal and substantially passing the modulated RF signal. The cancellation module cancels the blocking signal by generating an injection signal representative of the blocking signal, combining the blocking signal with the injection signal to produce an error signal, updating the injection signal based on the error signal and using the injection signal to cancel the blocking signal from the amplified inbound RF signal.

Abstract: A receiver architecture for canceling blocking signals in the receive path includes a low noise amplifier for receiving and amplifying an inbound RF signal to produce an amplified inbound signal, in which the inbound RF signal includes a modulated RF signal and a blocking signal, and a cancellation module for substantially canceling the blocking signal from the amplified inbound RF signal and substantially passing the modulated RF signal. The cancellation module cancels the blocking signal by generating an injection signal representative of the blocking signal, combining the blocking signal with the injection signal to produce an error signal, updating the injection signal based on the error signal and using the injection signal to cancel the blocking signal from the amplified inbound RF signal.

Abstract: A near field RFID system includes an RFID reader and an RFID tag. The RFID reader includes a transmit path and a receive path, wherein the transmit path includes: an encoding section coupled to convert data into encoded data; a digital to analog conversion module coupled to convert the encoded data into an analog encoded signal; a power amplifier coupled to amplify the analog encoded signal; and a plurality of coils coupled to generate a plurality of electromagnetic fields from the analog encoded signal. The RFID tag that includes: a coil coupled to generate a current and a recovered signal from at least one of the plurality of electromagnetic fields; a power recovery circuit coupled to generate a voltage from the current; and a data processing section coupled to process the recovered signal, wherein the data processing section is powered via the voltage.