Patent ID: 8099048

Claim:
A wireless communication system comprising: an antenna; a receive/transmit interdigital transducer (IDT) configured to produce a surface acoustic wave (SAW) output when excited by an electrical signal received from the antenna, and further configured to output, to the antenna, an electrical signal when excited by a SAW output; and first and second reflecting IDTs, each configured to passively reflect the SAW output from the receive/transmit IDT back to the receive/transmit IDT, which excites the receive/transmit IDT to output, to the antenna, first and second electrical signals from which the antenna respectively outputs first and second RF return signals; the terminals of the first reflecting IDT being exclusively open circuit or closed circuit for the first RF return signal to be a reference return signal; and the reflecting IDTs being different distances from the receive/transmit IDT so that the SAW outputs reflected by the first and second reflecting IDTs reach the receive/transmit IDT at different times.