Adaptable detection threshold for RFID tags and chips
First Claim
Patent Images
1. A method for a circuit of a Radio Frequency Identification (RFID) tag, the method including:
- receiving a modulated wireless RF input signal;
deriving an analog output signal responsive to the modulated wireless RF input signal at an envelope detector;
deriving a first unfiltered digital output signal responsive to the analog output signal and to a first analog decision threshold at a first slicer circuit;
deriving a second unfiltered digital output signal responsive to the analog output signal and to a second analog decision threshold at a second slicer circuit; and
deriving a filtered digital output signal at a selection circuit by selecting one of the first and second unfiltered digital outputs at a multiplexer of the selection circuit and configuring the multiplexer by a digital decision circuit based on a performance criterion.
1 Assignment
0 Petitions
Accused Products
Abstract
RFID tags, tag circuits, and methods are provided that reduce at least in part the distortion to received wireless signals, which is caused by interference in the environment. Two or more thresholds are used to digitize the received signal implemented by two or more demodulators. Multiple low pass and digital filters may be implemented with the demodulators, allowing removal of narrow pulses caused by the interference and reduction of beat tone amplitude.
-
Citations
16 Claims
-
1. A method for a circuit of a Radio Frequency Identification (RFID) tag, the method including:
-
receiving a modulated wireless RF input signal; deriving an analog output signal responsive to the modulated wireless RF input signal at an envelope detector; deriving a first unfiltered digital output signal responsive to the analog output signal and to a first analog decision threshold at a first slicer circuit; deriving a second unfiltered digital output signal responsive to the analog output signal and to a second analog decision threshold at a second slicer circuit; and deriving a filtered digital output signal at a selection circuit by selecting one of the first and second unfiltered digital outputs at a multiplexer of the selection circuit and configuring the multiplexer by a digital decision circuit based on a performance criterion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for a circuit of a Radio Frequency Identification (RFID) tag, the method including:
-
receiving a modulated wireless RF input signal; deriving an analog output signal responsive to the modulated wireless RF input signal at an envelope detector; applying power to a first and second slicer circuits until a performance criterion is met, the performance criterion signifying that a frame synch has been detected; selecting one of the first and second slicer circuits at a selection circuit to generate an unfiltered digital output; discontinuing applying power to the unselected one of the first and second slicer circuits; and deriving a filtered digital output signal at the selection circuit. - View Dependent Claims (13, 14, 15, 16)
-
Specification