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US 11,635,402 B2Granted
Subsoil moisture monitoring system including battery-less wireless chipless sensors
AssigneePurdue Research Foundation
InventorsSarath Gopalakrishnan, Jose Waimin, Rahim Rahimi, Nithin Raghunathan
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Abstract
A batteryless, chipless, sensor is disclosed which includes a substrate, at least two conductive strips disposed on the substrate, a passivation layer encasing the substrate and the at least two conductive strips, wherein the conductive strips are adapted to respond to an interrogation signal from a reader having a first polarization, with a response signal at a second polarization different than the first polarization.
Claims20
A batteryless, chipless, sensor, comprising:
- a substrate;
- at least two conductive strips coupled to each other and disposed in a meandered profile on the substrate;
- and
- a passivation layer encasing the substrate and the at least two conductive strips,
- wherein the conductive strips are adapted to respond to an interrogation signal from a reader having a first polarization, with a response signal at a second polarization different than the first polarization,
- wherein the lumped parameters are defined based on:
- L
- meander
- =
- 0
- .
- 2
-
- L
-
- {
- [
- 1
- .
- 4
-
- 813
-
- log
-
- (
- 2
-
- L
- a
- )
- ]
- 1
- .
- 0
-
- 1
-
- 2
- -
- 0
- .
- 6
-
- 1
-
- 88
- }
-
- µH
- C
- m
-
- e
-
- a
-
- nder
- =
- C
- b
-
- e
-
- n
-
- d
- N
- where N is the number of bends in the meandered profile,
- L is the total length of the meander profile,
- α is the radius of the trace, and
- Cbend is the capacitance between adjacent bends.
69 more elements
A system of determining soil conditions, comprising:
- one or more ground interrogating devices, each configured to radiate a wireless interrogating signal at a first polarization;
- a plurality of ground-embedded battery-less and chipless sensors, each comprising:
- a substrate,
- at least two conductive strips coupled to each other and disposed in a meandered profile on the substrate, and
- a passivation layer encasing the substrate and the at least two conductive strips,
- wherein the conductive strips are adapted to receive the interrogation signal from the one or more ground interrogating devices, and in response thereto provide a response signal at a second polarization different than the first polarization;
- wherein the response signal corresponds to a plurality of soil variable associated with soil conditions;
- a server configured to receive signals from the one or more ground interrogating devices;
- and
- at least one input/output device in communication with the server and configured to provide control signals to the one or more ground interrogating devices and to receive data associated with the soil variable associated with soil conditions,
- wherein the lumped parameters are defined based on:
- L
- meander
- =
- 0
- .
- 2
-
- L
-
- {
- [
- 1
- .
- 4
-
- 813
-
- log
-
- (
- 2
-
- L
- a
- )
- ]
- 1
- .
- 0
-
- 1
-
- 2
- -
- 0
- .
- 6
-
- 1
-
- 88
- }
-
- µH
- C
- m
-
- e
-
- a
-
- nder
- =
- C
- b
-
- e
-
- n
-
- d
- N
- where N is the number of bends in the meandered profile,
- L is the total length of the meander profile,
- a is the radius of the trace, and
- Cbend is the capacitance between adjacent bends.
74 more elements
Dependencies are inferred from the claim text.