SYSTEMS AND METHODS USING LOAD MODULATION FOR WIRELESS COMMUNICATION

摘要

A wireless reader has a processor within an integrated circuit, and the processor is used to generate a primary signal to be wirelessly transmitted from an antenna of the wireless reader to a wireless tag. A transmit pin of the integrated circuit is coupled to the processor by a signal path in the integrated circuit. The transmit pin outputs the primary signal from the integrated circuit to the antenna for wireless transmission of the primary signal to the wireless tag. A sensor is configured to sense current or voltage variations of the primary signal at a point in the signal path between the processor and the transmit pin, and a signal extraction unit is configured to extract, based on the current or voltage variations, a data signal wirelessly transmitted by the wireless tag to the wireless reader via load modulation of the primary signal.

主权项

1. A radio-frequency identification (RFID) system, comprising:
an RFID reader in wireless communication with an RFID tag, the RFID reader having an integrated circuit, a matching network, an antenna, and a transmit pin for outputting a primary signal from the integrated circuit to the antenna for wireless transmission of the primary signal from the antenna to the RFID tag, wherein the RFID reader is configured to wirelessly receive a data signal from the RFID tag via load modulation of the primary signal by the RFID tag thereby inducing current or voltage variations of the primary signal in a transmitter portion of the integrated circuit, wherein the antenna is coupled to the transmit pin through the matching network, and wherein the integrated circuit has a signal extraction unit and a sensor, the transmitter portion of the integrated circuit comprising:
a processor;a modulator coupled to the processor, the modulator configured to modulate a reference signal with an input signal from the processor, thereby providing the primary signal; andan amplifier coupled to the modulator and the transmit pin, the amplifier configured to amplify the primary signal for transmission of the primary signal through the transmit pin and the matching network to the antenna, wherein the sensor is configured to sense the current or voltage variations in the transmitter portion at a point in a signal path from the processor to the transmit pin, and wherein the signal extraction unit is configured to extract the data signal based on the sensor.