# US 2019/0245384 A1 · Detuning for a resonant wireless power transfer system including cooperative power sharing

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- Number: US 2019/0245384 A1
- Document ID: US20190245384A1
- Status: Published application
- Kind: A1
- Application number: 15/892,155
- Filed: 2018-02-08
- Published: 2019-08-08
- Earliest claimed: 2018-02-08
- Assignees: Massachusetts Institute of Technology
- Applicants: Massachusetts Institute of Technology
- Inventors: Anantha P. Chandrakasan; Nachiket V. Desai; Chiraag Juvekar
- Web page: https://patentgrep.com/patent/US20190245384A1

## CPC

- H03K 7/08: Duration or width modulation {; Duty cycle modulation}
- H02J 50/05: using capacitive coupling
- H02J 50/12: of the resonant type
- H04B 5/26: using coils
- H04B 5/79: for data transfer in combination with power transfer
- H01F 38/14: Inductive couplings
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H04B: TRANSMISSION
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

Wireless resonant inductive power receivers for achieving detuning for a resonant wireless power transfer system including cooperative power sharing is described. Cooperative power sharing allows for detuning one or more wireless received coupled to a wireless charger to alter the power received at each wireless receiver

## Claims

### Claim 1

A wireless resonant inductive power receiver for cooperative power sharing between two or more wireless resonant inductive power receivers coupled to a wireless resonant power charger, the wireless resonant inductive power receiver comprising:
a first inductive element resonating at a frequency; and
a second inductive element wirelessly coupled to the second inductive element.

### Claim 2 (depends on 1)

The wireless resonant inductive power receiver of claim 1, wherein the resonant frequency is based upon an impedance presented to the second inductive element.

### Claim 3 (depends on 2)

The wireless resonant inductive power receiver of claim 2, wherein the second inductive element is further coupled to a duty cycle control, the duty cycle control configured to adjust the impedance presented to the second inductive element.

### Claim 4 (depends on 3)

The wireless resonant inductive power receiver of claim 3, wherein the duty cycle control is configured to adjust the impedance presented to the second inductive element so that the resonant frequency is equal to a resonant frequency of the wireless charger.

### Claim 5 (depends on 3)

The wireless resonant inductive power receiver of claim 3, wherein the duty cycle control is configured to adjust the impedance presented to the second inductive element so that the resonant frequency is not equal to a resonant frequency of the wireless charger.

### Claim 6 (depends on 1)

The wireless resonant inductive power receiver of claim 1, wherein the second inductive element is further coupled to an auxiliary rectifier, wherein the impedance presented to the second inductive element comprises an input impedance of the auxiliary rectifier.

### Claim 7 (depends on 6)

The wireless resonant inductive power receiver of claim 6, wherein the input impedance of the auxiliary rectifier is based upon a duty cycle of the auxiliary rectifier.

### Claim 8 (depends on 1)

The wireless resonant inductive power receiver of claim 1, wherein the first inductive element is further coupled to a main rectifier and the second inductive element is further coupled to an auxiliary rectifier.

### Claim 9 (depends on 1)

The wireless inductive power receiver of claim 1, wherein an output of the main rectifier and an output of the auxiliary rectifier are configured to supply power to a load.

### Claim 10 (depends on 1)

The wireless inductive power receiver of claim 1, wherein the first inductive element is larger in physical size than the second inductive element.

### Claim 11 (depends on 1)

The wireless inductive power receiver of claim 1, wherein the resonant frequency is based upon a capacitance coupled to the main inductive element.

### Claim 12 (depends on 1)

The wireless inductive power receiver of claim 1, further comprising a third inductive element wirelessly coupled to the first inductive element.

### Claim 13 (depends on 12)

The wireless inductive power receiver of claim 12, wherein the wherein the resonant frequency is based upon an impedance presented to the third inductive element.

### Claim 14 (depends on 12)

The wireless resonant inductive power receiver of claim 12, wherein third inductive element is further coupled to a second duty cycle control, the second duty cycle control configured to adjust the impedance presented to the third inductive element.

### Claim 15 (depends on 1)

The wireless resonant inductive power receiver of claim 1, wherein the first inductive element is one of a plurality of main inductive elements.

### Claim 16 (depends on 15)

The wireless resonant inductive power receiver of claim 15, wherein each at least one of the plurality of main inductive elements is coupled to at least one of a plurality of main rectifiers.

### Claim 17 (depends on 1)

The wireless resonant inductive power receiver of claim 1, wherein the second inductive element is one of a plurality of auxiliary inductive elements.

### Claim 18

A wireless resonant inductive power receiver for cooperative power sharing between two or more wireless resonant inductive power receivers coupled to a wireless resonant power charger, comprising:
a main inductive coil resonating at a frequency and wirelessly coupled to an auxiliary inductive coil;
an auxiliary rectifier coupled to the auxiliary inductive coil, wherein the resonant frequency of the main inductive coil is based upon a duty cycle of the auxiliary rectifier; and
a detuning engine configured to control the duty cycle of the auxiliary rectifier.

### Claim 19 (depends on 18)

The wireless resonant inductive power receiver of claim 18, wherein the detuning engine is further configured to detect a second wireless resonant inductive power receiver in proximity.

### Claim 20 (depends on 119)

The wireless resonant inductive power receiver of claim 119, wherein the detuning engine is further configured to adjust the duty cycle of the auxiliary rectifier based upon the detected second wireless resonant inductive power receiver.

### Claim 21 (depends on 18)

The wireless resonant inductive power receiver of claim 18, wherein the detuning engine is configured to control the duty cycle so that power from a wireless charger is redistributed between the wireless resonant inductive power receiver and the second wireless resonant inductive power receiver.

### Claim 22 (depends on 18)

The wireless resonant inductive power receiver of claim 18, wherein the detuning engine is configured to adjust the duty cycle so that the resonant frequency of the main coil is adjusted away from a resonant charging frequency of a wireless charger when a second wireless resonant inductive power receiver is in proximity to the wireless resonant inductive power receiver.

### Claim 23

A method for detuning a wireless resonant inductive power receiver comprising:
determining a desired duty cycle; and
adjusting a resonant frequency of a main inductive element of a wireless receiver,
wherein adjusting the resonant frequency of the main inductive element comprises adjusting an impedance presented to an auxiliary inductive element of the wireless receiver based upon the determined, desired duty cycle.

### Claim 24 (depends on 22)

The method of claim 22, wherein the main inductive element is wirelessly coupled to the auxiliary inductive element.

### Claim 25 (depends on 22)

The method of claim 22, wherein the auxiliary inductive element is coupled to an auxiliary rectifier.

### Claim 26 (depends on 24)

The method of claim 24, wherein the impedance presented to the auxiliary inductive element comprises an impedance at an input of auxiliary rectifier.

### Claim 27 (depends on 22)

The method of claim 22, wherein adjusting an impedance presented to the auxiliary inductive element comprises adjusting a duty cycle of an auxiliary rectifier based upon the determined, desired duty cycle.

### Claim 28 (depends on 26)

The method of claim 26, wherein adjusting the duty cycle of the auxiliary rectifier comprises:
selecting a control voltage associated with the determine, desired duty cycle.

### Claim 29 (depends on 22)

The method of claim 22, wherein adjusting the resonant frequency of the main inductive element comprises adjusting the resonant frequency of the main inductive element to be effectively equal to a charging frequency.

### Claim 30 (depends on 22)

The method of claim 22, wherein adjusting the impedance presented to the auxiliary inductive element comprises adjusting the impedance presented to the auxiliary inductive element to be effectively open.

### Claim 31

A wireless resonant inductive power receiver coupled to a wireless resonant power charger, the wireless resonant inductive power receiver comprising:
a main inductive element resonating at a frequency; and
an auxiliary rectifier, wherein the resonant frequency of the main inductive element is based upon an impedance of the auxiliary rectifier.

### Claim 32 (depends on 30)

The wireless resonant inductive power receiver of claim 30, wherein the auxiliary rectifier is further coupled to an auxiliary inductive element.

### Claim 33 (depends on 31)

The wireless resonant inductive power receiver of claim 31, wherein the auxiliary inductive element is wirelessly coupled to the main inductive element.

### Claim 34 (depends on 30)

The wireless resonant inductive power receiver of claim 30, wherein the main inductive element is one of a plurality of main inductive elements.

### Claim 35 (depends on 30)

The wireless resonant inductive power receiver of claim 30, further comprising an auxiliary inductive element, wherein the auxiliary inductive element is one of a plurality of auxiliary inductive elements.

### Claim 36 (depends on 30)

The wireless resonant inductive power receiver of claim 30, wherein the main inductive element is coupled to a main rectifier.

### Claim 37 (depends on 35)

The wireless resonant inductive power receiver of claim 35, wherein the main rectifier is coupled to a load, wherein the rectifier is configured to deliver power to the coupled load.

### Claim 38 (depends on 35)

The wireless resonant inductive power receiver of claim 35, wherein the main rectifier is configured to rectify a current from the main inductive element.