Systems and methods for battery-less wirelessly powered dielectric sensors

Patent metadata

Field	Value
Publication number	US-12320769-B2
Application number	US-201917287432-A
Country	US
Kind code	B2
Filing date	Nov 4, 2019
Priority date	Nov 19, 2018
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

Wirelessly powered dielectric sensor in accordance with embodiments of the invention are disclosed. In many embodiments, a wirelessly powered dielectric sensor includes an RF-power receiving antenna that receives electromagnetic power, a power management unit (PMU) including a capacitor to rectify and store the electromagnetic power, and a dielectric constant sensing sensor, where the PMU monitors harvested energy and operates the dielectric sensing sensor; and where the dielectric sensing sensor senses a dielectric constant of a material that is in close proximity.

First claim

What is claimed is:

1. A wirelessly powered dielectric sensor, comprising:
an RF-power receiving antenna that receives electromagnetic power;
a power management unit (PMU) comprising a first capacitor to rectify and store the electromagnetic power; and
a dielectric constant sensing sensor comprising an oscillator comprising a second capacitor and an inductor;
wherein the PMU monitors harvested energy and operates the dielectric sensing sensor;
wherein the dielectric sensing sensor senses a dielectric constant of a material that is in close proximity by capacitance change of the second capacitor, and which sensed capacitance change of the second capacitor produces a shift in the oscillation frequency of the oscillator.

2. The wirelessly powered dielectric sensor of claim 1 , wherein the PMU further comprises a voltage reference circuit, a comparator, a low drop-out (LDO) regulator, wherein the first capacitor is an on-chip storage capacitor.

3. The wirelessly powered dielectric sensor of claim 2 , wherein the PMU monitors a voltage on the first capacitor and turns a transmitter circuit on when there is sufficient energy in the first capacitor.

4. The wirelessly powered dielectric sensor of claim 3 , wherein the PMU generates enable signals to turn on the low drop-out regulator to generate a regulated voltage V reg for the dielectric sensing sensor and to turn on the dielectric sensing sensor.

5. The wirelessly powered dielectric sensor of claim 1 , wherein the receiving antenna is an on-chip antenna.

6. The wirelessly powered dielectric sensor of claim 1 , wherein the first capacitor is an on-chip capacitor.

7. The wirelessly powered dielectric sensor of claim 1 , further comprising a transmitting on-chip antenna, wherein the transmitting on-chip antenna is used to wirelessly transmit a signal.

8. The wirelessly powered dielectric sensor of claim 7 , wherein the oscillator is a dielectric sensing oscillator which drives the transmitting on-chip antenna to radiate back a signal at the oscillation frequency of the oscillator.

9. The wirelessly powered dielectric sensor of claim 7 , wherein the transmitting on-chip antenna is used to transmit the signal using at least one of a wired communication channel or a wireless communication channel.

10. The wirelessly powered dielectric sensor of claim 1 , wherein the oscillator produces a frequency shift depending on the value of the dielectric constant being measured.

11. The wirelessly powered dielectric sensor of claim 1 , wherein the PMU operates the dielectric sensing sensor in duty cycle mode.

12. The wirelessly powered dielectric sensor of claim 1 , wherein the dielectric sensing sensor is used to receive a command where there is a nonconductive isolating layer between a user providing the command and the wirelessly powered dielectric sensor.

13. The wirelessly powered dielectric sensor of claim 1 , wherein the second capacitor of the dielectric sensing sensor comprises a metaloxide-metal capacitor (MOMCAP) that provides different capacitance for different materials.

14. A method for wirelessly powering a dielectric sensor, comprising
receiving electromagnetic power using an RF-power receiving antenna;
rectifying and storing the electromagnetic power using a first capacitor included in a power management unit (PMU);
sensing a dielectric constant using a dielectric constant sensing sensor comprising an oscillator comprising a second capacitor and an inductor;
wherein the PMU monitors harvested energy and operates the dielectric sensing sensor;
wherein the dielectric sensing sensor senses a dielectric constant of a material that is in close proximity by capacitance change of the second capacitor, and which sensed capacitance change of the second capacitor produces a shift in the oscillation frequency of the oscillator.

15. The method of claim 14 , wherein the PMU further comprises a voltage reference circuit, a comparator, a low drop-out (LDO) regulator, wherein the first capacitor is an on-chip storage capacitor.

16. The method of claim 15 , wherein the PMU monitors a voltage on the first capacitor and turns a transmitter circuit on when there is sufficient energy in the first capacitor.

17. The method of claim 16 , wherein the PMU generates enable signals to turn on the low drop-out regulator to generate a regulated voltage Vreg for the dielectric sensing sensor and to turn on the dielectric sensing sensor.

18. The method of claim 14 , wherein the receiving antenna is an on-chip antenna.

19. The method of claim 14 , wherein the first capacitor is an on-chip capacitor.

20. The method of claim 14 , further comprising wirelessly transmitting a signal using a transmitting on-chip antenna.

Assignees

• Univ California

Inventors

• Babakhani Aydin
• Sun Yuxiang

Classifications

• H02J2105/46

  Medical devices, medical implants or life supporting devices · CPC title

• G01N27/221

  by investigating the dielectric properties (using microwaves G01N22/00; measuring loss factors or dielectric constants per se G01R27/26) · CPC title

• A61B2560/0219

  of externally powered implanted units · CPC title

• A61B5/0031

  Implanted circuitry · CPC title

• H02J50/001

  Energy harvesting or scavenging · CPC title