Tags, wireless communication systems, tag communication methods, and wireless communications methods

Abstract

Tags, wireless communication systems, tag communication methods, and wireless communications methods are described. In one aspect, a tag includes a plurality of antennas configured to receive a plurality of first wireless communication signals comprising data from a reader, a plurality of rectifying circuits coupled with respective individual ones of the antennas and configured to provide rectified signals corresponding to the first wireless communication signals, wherein the rectified signals are combined to produce a composite signal, an adaptive reference circuit configured to vary a reference signal responsive to the composite signal, a comparator coupled with the adaptive reference circuit and the rectifying circuits and configured to compare the composite signal with respect to the reference signal and to output the data responsive to the comparison, and processing circuitry configured to receive the data from the comparator and to process the data.

1 . A tag comprising: 
 a plurality of antennas configured to receive a plurality of first wireless communication signals comprising data from a reader;    a plurality of rectifying circuits coupled with respective individual ones of the antennas and configured to provide rectified signals corresponding to the first wireless communication signals, wherein the rectified signals are combined to produce a composite signal;    an adaptive reference circuit configured to vary a reference signal responsive to the composite signal;    a comparator coupled with the adaptive reference circuit and the rectifying circuits and configured to compare the composite signal with respect to the reference signal and to output the data responsive to the comparison; and    processing circuitry configured to receive the data from the comparator and to process the data.    
   
   
       2 . The tag of  claim 1  wherein the antennas individually comprise a meander line.  
   
   
       3 . The tag of  claim 1  wherein the antennas individually comprise a compressed dipole antenna.  
   
   
       4 . The tag of  claim 3  further comprising a ground plane spaced from the antennas.  
   
   
       5 . The tag of  claim 4  further comprising a metal reflector spaced from the ground plane.  
   
   
       6 . The tag of  claim 1  wherein the rectifying circuits comprise cascaded voltage doubling circuits.  
   
   
       7 . The tag of  claim 1  wherein the rectifying circuits individually comprise a plurality of diodes configured as a full-wave rectifier circuit.  
   
   
       8 . The tag of  claim 1  wherein the rectifying circuits comprise a plurality of diodes and a cathode of a diode of one of the rectifying circuits and a cathode of a diode of another of the rectifying circuits are coupled via a common node.  
   
   
       9 . The tag of  claim 8  wherein the common node is coupled to an input of the comparator.  
   
   
       10 . The tag of  claim 1  wherein the processing circuitry is configured to control the tag to output a plurality of second wireless communication signals comprising backscatter signals for communication to the reader.  
   
   
       11 . The tag of  claim 10  wherein the processing circuitry is configured to control the communication of the second wireless communication signals to implement radio frequency identification device communications with the reader.  
   
   
       12 . The tag of  claim 10  wherein the processing circuitry is configured to control at least one of the antennas to output the second wireless communication signals.  
   
   
       13 . The tag of  claim 10  wherein the processing circuitry is configured to control the plurality of antennas to output the second wireless communication signals.  
   
   
       14 . The tag of  claim 1  further comprising a battery configured to provide electrical energy to the processing circuitry.  
   
   
       15 . The tag of  claim 1  wherein the antennas are tuned to substantially the same frequency band.  
   
   
       16 . The tag of  claim 1  wherein one of the antennas is substantially tuned to a first frequency band and another of the antennas is substantially tuned to a second frequency band different than the first frequency band.  
   
   
       17 . A wireless communication system comprising: 
 a reader configured to output a plurality of first wireless communication signals comprising data; and    a tag comprising a plurality of antennas configured to receive the first wireless communication signals from the reader, processing circuitry configured to receive the data of the first wireless communication signals and to control backscatter modulation of radio frequency energy to communicate a plurality of second wireless communication signals to the reader, and a battery configured to provide operational electrical energy to the processing circuitry.    
   
   
       18 . The system of  claim 17  wherein the tag is configured to combine a plurality of electrical signals corresponding to the first wireless communication signals.  
   
   
       19 . The system of  claim 18  wherein the tag comprises a plurality of rectifying circuits coupled with respective ones of the antennas and configured to provide the electrical signals comprising rectified signals.  
   
   
       20 . The system of  claim 18  wherein the tag comprises an adaptive reference circuit configured to provide a reference signal responsive to the combined electrical signals, and a comparator configured to compare the combined electrical signals with the reference signal.  
   
   
       21 - 43 . (canceled)