Communication system, interrogators and communication methods
First Claim
1. A communication system comprising:
- a communication device configured to receive a continuous wave signal and to output a modulated continuous wave signal responsive to the receiving; and
an interrogator configured to reduce an amplitude of a component of the modulated continuous wave signal having a frequency of the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency;
wherein the interrogator is configured to reduce the amplitude of the component prior to demodulation of the modulated continuous wave signal.
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Abstract
The present invention includes backscatter communication systems, interrogators, methods of communicating in a backscatter system, and backscatter communication methods. According to one aspect of the present invention, a backscatter communication system includes an interrogator including a transmitter configured to output a forward link communication and a receiver configured to receive a return link communication having a carrier signal, the receiver being configured to reduce the amplitude of the carrier signal of the return link communication; and a communication device configured to modulate the carrier signal to communicate the return link communication responsive to reception of the forward link communication.
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Citations
64 Claims
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1. A communication system comprising:
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a communication device configured to receive a continuous wave signal and to output a modulated continuous wave signal responsive to the receiving; and an interrogator configured to reduce an amplitude of a component of the modulated continuous wave signal having a frequency of the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the interrogator is configured to reduce the amplitude of the component prior to demodulation of the modulated continuous wave signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An interrogator comprising:
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a receiver configured to receive a continuous wave signal having a frequency and a modulated continuous wave signal, the receiver being further configured to reduce an amplitude of a component of the modulated continuous wave signal having the frequency of the continuous wave signal using the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the receiver is configured to reduce the amplitude of the component prior to demodulation of the modulated continuous wave signal. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An interrogator comprising:
a receiver configured to receive a local signal and a communication signal, the receiver being further configured to adjust the local signal responsive to the communication signal and to reduce an amplitude of a component of the communication signal having a first frequency using the adjusted local signal while substantially maintaining an amplitude of another component of the communication signal having another frequency. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A communication method comprising:
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communicating a continuous wave signal having a frequency; communicating a modulated continuous wave signal responsive to the continuous wave signal using a communication device; receiving the modulated continuous wave signal; and reducing an amplitude of a component of the modulated continuous wave signal having the frequency of the continuous wave signal after the receiving while substantially maintaining an amplitude of a component of the modulated continuous wave signal having a frequency different than the frequency of the continuous wave signal; wherein the reducing comprises reducing prior to demodulation of the modulated continuous wave signal. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A communication method comprising:
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providing a continuous wave signal; modulating the continuous wave signal providing a modulated continuous wave signal to communicate information; receiving the modulated continuous wave signal; and after the receiving, reducing an amplitude of a component of the modulated continuous wave signal having a frequency of the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the reducing comprises reducing prior to demodulation of the modulated continuous wave signal. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42)
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43. A communication method comprising:
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providing a local signal; receiving a communication signal; and after the receiving, reducing an amplitude of a first component of the communication signal while substantially maintaining an amplitude of a second component of the communication signal, the reducing comprising adjusting the local signal responsive to the communication signal and combining the communication signal and the local signal after the adjusting. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50, 51)
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52. A coherent backscatter system communication method comprising:
reducing an amplitude of a frequency component of a modulated continuous wave signal using a receiver, the reducing including; adjusting an amplitude and a phase of a local continuous wave signal providing an adjusted continuous wave signal; and summing the adjusted continuous wave signal with the modulated continuous wave signal.
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53. A communication system comprising:
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a communication device configured to receive a continuous wave signal and to output a modulated continuous wave signal responsive to the receiving; and an interrogator configured to reduce an amplitude of a component of the modulated continuous wave signal having a frequency of the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the interrogator is configured to receive the continuous wave signal and to reduce the amplitude of the component of the modulated continuous wave signal using the continuous wave signal including matching an amplitude of the continuous wave signal with an amplitude of the modulated continuous wave signal, adjusting a phase of the continuous wave signal, and summing the adjusted continuous wave signal with the modulated continuous wave signal.
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54. An interrogator comprising:
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a receiver configured to receive a continuous wave signal having a frequency and a modulated continuous wave signal, the receiver being further configured to reduce an amplitude of a component of the modulated continuous wave signal having the frequency of the continuous wave signal using the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the receiver is configured to reduce the amplitude of the component of the modulated continuous wave signal using the continuous wave signal including matching an amplitude of the continuous wave signal with the amplitude of the modulated continuous wave signal, adjusting a phase of the continuous wave signal, and summing the adjusted continuous wave signal with the modulated continuous wave signal.
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55. A communication method comprising:
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communicating a continuous wave signal having a frequency; communicating a modulated continuous wave signal responsive to the continuous wave signal using a communication device; receiving the modulated continuous wave signal; reducing an amplitude of a component of the modulated continuous wave signal having the frequency of the continuous wave signal after the receiving while substantially maintaining an amplitude of a component of the modulated continuous wave signal having a frequency different than the frequency of the continuous wave signal; and providing a local continuous wave signal and the reducing comprises reducing using the local continuous wave signal including matching an amplitude of the local continuous wave signal with an amplitude of the modulated continuous wave signal, adjusting a phase of the local continuous wave signal, and summing the adjusted local continuous wave signal with the modulated continuous wave signal.
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56. A communication method comprising:
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providing a continuous wave signal; modulating the continuous wave signal providing a modulated continuous wave signal to communicate information; receiving the modulated continuous wave signal; and after the receiving, reducing an amplitude of a component of the modulated continuous wave signal having a frequency of the continuous wave signal while substantially maintaining an amplitude of another component of the modulated continuous wave signal having another frequency; wherein the reducing comprises matching an amplitude of the continuous wave signal with an amplitude of the modulated continuous wave signal, adjusting a phase of the continuous wave signal, and summing the continuous wave signal and the modulated continuous wave signal after the matching and the adjusting.
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57. A method comprising:
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interrogating a radio frequency identification (RFID) tag using an interrogator to transmit a wireless spread spectrum signal comprising a wireless command signal followed by a wireless continuous wave signal, the interrogator further generating a local continuous wave signal having a common frequency with the wireless continuous wave signal; receiving a return signal using the interrogator, the return signal comprising a carrier component and a side band component, the side band component including information from the RFID tag sent in response to the command using backscatter communication; adjusting the local continuous wave signal to generate an adjusted local continuous wave signal; and reducing an amplitude of the carrier component using the adjusted local continuous wave signal and substantially maintaining an amplitude of the side band component, wherein reducing the amplitude of the carrier component comprises summing the return signal with the adjusted local continuous wave signal. - View Dependent Claims (58, 59, 60, 61)
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62. A system comprising:
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an RFID tag comprising a half wavelength dipole antenna, the RFID tag configured to receive a wireless spread spectrum signal comprising a wireless command signal followed by a wireless continuous wave signal, and to backscatter reply information onto the wireless continuous wave signal in response to the command signal; and an interrogator comprising; a transmitter to transmit the wireless spread spectrum signal; a first coupler to provide a local continuous wave signal having a common frequency with the wireless continuous wave signal; a receiver to receive a return signal comprising a carrier component and a side band component, the side band component including the reply information from the RFID tag; and circuitry to adjust the local continuous wave signal to generate an adjusted local continuous wave signal, and to reduce an amplitude of the carrier component of the return signal using the adjusted local continuous wave signal while substantially maintaining an amplitude of the side band component, wherein the circuitry comprises a second coupler to sum the return signal with the adjusted local continuous wave signal. - View Dependent Claims (63, 64)
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Specification