Patent ID: 9477857
Filing Date: 2016-10-25
CPC Classification: G02B,G06K,H04B,H04J

Claim Text:
1. A surface acoustic wave (SAW)-based coherence multiplexing system, comprising: a plurality of spaced apart SAW tags each comprising: at least one SAW transducer including an interdigitated thin metal film electrode structure on a piezoelectric crystal substrate; a first SAW reflector comprising a first thin metal film structure on said piezoelectric crystal substrate positioned a first minimum distance from said SAW transducer; and at least a second SAW reflector comprising a second thin metal film structure on said piezoelectric crystal substrate positioned a second minimum distance not equal to said first minimum distance, and a transceiver including (i) a wireless transmitter having a signal source providing a source signal and circuitry for transmitting interrogation pulses including at least a first and a second interrogation pulse different from said first interrogation pulse toward said plurality of SAW tags, and (ii) a wireless receiver for receiving and processing received signals response signals from said plurality of SAW tags, said receiver receiving scrambled signals being a convolution of said interrogation pulses with said response signals from said plurality of SAW tags, and including a computing device which implements an algorithm that correlates said interrogation pulses or said source signal against said scrambled signals to generate tag responses for each of said plurality of SAW tags; wherein said first SAW reflector and said second SAW reflector are both configured to have a different center frequency.