RADIO FREQUENCY TRANSPONDER SYSTEM
First Claim
Patent Images
1. A radio frequency transponder, comprising:
- a substrate; and
a plurality of planar antennas on the substrate, wherein each antenna has a shape configured to determine a corresponding resonant frequency of the antenna, wherein the antenna is configured to cause a phase difference between backscattered signals generated in response to excitation of the antenna by orthogonally polarized interrogation signals at the resonant frequency, and wherein the phase difference represents a code of the antenna andwherein the antennas have respective different resonant frequencies, and wherein the codes determined from the phase differences between the backscattered signals at each of the resonant frequencies are configured to generate a unique code for the transponder.
3 Assignments
0 Petitions
Accused Products
Abstract
A radio frequency transponder is disclosed. In one embodiment, the transponder includes: a substrate and at least one planar antenna on the substrate, the antenna having a shape determining a corresponding resonant frequency of the antenna, wherein the antenna is configured to cause a phase difference between backscattered signals generated in response to excitation of the antenna by orthogonally polarized interrogation signals at the resonant frequency, and the phase difference represents a code of the antenna.
-
Citations
21 Claims
-
1. A radio frequency transponder, comprising:
-
a substrate; and a plurality of planar antennas on the substrate, wherein each antenna has a shape configured to determine a corresponding resonant frequency of the antenna, wherein the antenna is configured to cause a phase difference between backscattered signals generated in response to excitation of the antenna by orthogonally polarized interrogation signals at the resonant frequency, and wherein the phase difference represents a code of the antenna and wherein the antennas have respective different resonant frequencies, and wherein the codes determined from the phase differences between the backscattered signals at each of the resonant frequencies are configured to generate a unique code for the transponder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A radio-frequency identification transponder, comprising:
-
a dielectric substrate; and a plurality of antennas formed on the substrate and configured to generate backscattered radiation at different resonant frequencies for different polarizations, wherein the antennas comprise a plurality of load elements each of which is configured to determine a phase difference of the different polarizations of the backscattered radiation, and wherein the phase difference represents a value of a code of the transponder. - View Dependent Claims (15)
-
-
16. A radio frequency transponder system, comprising:
-
a radio-frequency identification transponder, comprising;
i) a dielectric substrate, ii) a plurality of antennas formed on the substrate and configured to generate backscattered radiation at different resonant frequencies for different polarizations and iii) load elements of the antennas each of which is configured to determine a phase difference of the different polarizations of the backscattered radiation, wherein the phase difference represents a value of a code of the transponder; anda reader for generating the interrogation signals and reading the backscattered signals to extract the code.
-
-
17. A radio frequency reader for interrogating a radio frequency transponder, comprising:
-
a frequency interface unit configured to transmit a plurality of polarized interrogation signals and receive a plurality of backscattered signals from the transponder in response; and a signal processing unit configured to determine a code of the transponder from the phase difference of the backscattered signals. - View Dependent Claims (18, 19)
-
-
20. A radio frequency process, comprising:
-
transmitting polarized interrogation signals; receiving backscattered signals including orthogonal components from a transponder in response; and determining a code of the transponder from the phase difference between the orthogonal components of the backscattered signals.
-
-
21. A radio frequency transponder, comprising:
-
means for transmitting polarized interrogation signals; means for receiving backscattered signals including orthogonal components from a transponder in response; and means for determining a code of the transponder from phase difference between the orthogonal components of the backscattered signals.
-
Specification