Wireless communication system using surface acoustic wave (SAW) second harmonic techniques
First Claim
Patent Images
1. 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.
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Accused Products
Abstract
A system is for encoding information on a passive surface acoustic wave (SAW) device. The system includes a requesting unit configured to wirelessly transmit an impulse signal. The impulse signal is a signal that includes only a single pulse. A SAW device has an interdigital transducer (IDT) configured to physically store coded data. The SAW device is configured to receive the impulse signal. In response to receiving the impulse signal, the SAW device excites the IDT to generate a coded signal that includes the stored coded data and frequency components at a fundamental frequency.
46 Citations
8 Claims
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1. A wireless communication system comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification