Passively coupled RFID receiver

摘要

A passively coupled RFID receiver is disclosed. The apparatus according to embodiments of the invention can reduce the cost of the RFID reader while significantly improving the linearity of the reader's receiver. An example system for reading RFID tags includes an active mixer passively connected to an antenna port to convert an incoming signal to a baseband signal. The baseband signal passes through a receive path, which may include other elements, and is ultimately provided to a processor that decodes the baseband signal. In some embodiments a complete RFID system making use of the passively coupled receiver includes an RFID transmitter that sends an RF carrier signal to cause the RFID tag to produce the incoming signal. In some embodiments a TX-RX coupler is connected to the transmitter, the receiver, and the antenna port, wherein the active mixer is passively connected to the antenna port through a receive port.

主权项

1. A system for reading RFID tags, the system comprising:
an antenna port to receive an incoming signal from an RFID tag; an active mixer passively connected to the antenna port to convert the incoming signal to a baseband signal; a processor to decode the baseband signal; and a transformer connected between the active mixer and the processor.