Abstract: RFID readers may be configured to recover multiple, collided RFID tag signals. An RFID reader may receive a collided reply waveform including at least first and second tag responses. The reader may determine that the collided reply waveform contains multiple tag responses and recover the first and second tag responses from the collided reply waveform. The reader may first recover the first tag response, reconstruct the first tag response, and subtract the reconstructed first tag response from the collided reply waveform to form a modified tag response. The reader may then recover the second tag response from the modified tag response.

Abstract: RFID readers may be configured to recover weak RFID tag signals from collisions with stronger RFID tag signals. An RFID reader may receive a combined tag response including a strong tag response and a weak tag response. The reader recovers the strong and weak tag responses using source separation. In one example, the reader may recover the strong tag response from the combined tag response and remove the recovered tag response from the combined tag response to form a modified tag response. The reader may then recover the weak tag response from the modified tag response.

Abstract: RFID readers may be configured to recover weak RFID tag signals from collisions with stronger RFID tag signals. An RFID reader may receive a combined tag response including a strong tag response and a weak tag response. The reader recovers the strong and weak tag responses using source separation. In one example, the reader may recover the strong tag response from the combined tag response and remove the recovered tag response from the combined tag response to form a modified tag response. The reader may then recover the weak tag response from the modified tag response.

Abstract: RFID readers, reader systems, and methods are provided that utilize double conversion for received tag response signals. A digitized signal is derived from the tag response signal by first shifting the response signal to about DC. The components of the digitized signal are then up converted and down converted and filtered such that only components around DC remain. The up converted and down converted signals may then be compared and one selected or the two combined after weighting to enhance demodulation and reduce circuit complexity.

Abstract: An RFID tag has a fuse that is adapted to store configuration data in a way that survives loss of power. The fuse can be one time programmable or many times programmable, and be implemented with a non-volatile memory. The configuration data becomes available to an operational component of the tag, such as at power up, controlling its performance.

Abstract: RFID tags, tag circuits, and methods adapting the reception bandwidth. A tag has a decoder for decoding a first received wireless signal subject to a reception bandwidth setting. The tag also has a selector switch for transitioning to a different setting, such as by switching to using a different filter. A subsequently received second signal is decoded subject to the new reception bandwidth setting.