U.S. patent application number 15/474396 was filed with the patent office on 2017-07-20 for wireless electric field power transfer system, method, transmitter and receiver therefor.
This patent application is currently assigned to Solace Power Inc.. The applicant listed for this patent is Solace Power Inc.. Invention is credited to Mohammed Jahangir ALAM, Sheikh Mominul ISLAM, Nagesh POLU, Nima SOLTANI.
Application Number | 20170207665 15/474396 |
Document ID | / |
Family ID | 47831201 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170207665 |
Kind Code |
A1 |
POLU; Nagesh ; et
al. |
July 20, 2017 |
WIRELESS ELECTRIC FIELD POWER TRANSFER SYSTEM, METHOD, TRANSMITTER
AND RECEIVER THEREFOR
Abstract
A wireless electric field power transmission system comprises: a
transmitter comprising a transmitter antenna, the transmitter
antenna comprising at least two conductors defining a volume
therebetween; and at least one receiver, wherein the transmitter
antenna transfers power wirelessly via electric field coupling when
the at least one receiver is within the volume.
Inventors: |
POLU; Nagesh; (Mount Pearl,
CA) ; ALAM; Mohammed Jahangir; (Mount Pearl, CA)
; ISLAM; Sheikh Mominul; (Mount Pearl, CA) ;
SOLTANI; Nima; (Mount Pearl, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Solace Power Inc. |
Mount Pearl |
|
CA |
|
|
Assignee: |
Solace Power Inc.
Mount Pearl
CA
|
Family ID: |
47831201 |
Appl. No.: |
15/474396 |
Filed: |
March 30, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13607474 |
Sep 7, 2012 |
9653948 |
|
|
15474396 |
|
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|
61532092 |
Sep 7, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 50/001 20200101;
B60L 53/36 20190201; H01Q 1/3216 20130101; H02J 50/10 20160201;
H03F 3/245 20130101; H02J 50/05 20160201; H02J 50/005 20200101;
B60L 53/122 20190201; H03F 2203/30031 20130101; H01Q 1/2225
20130101; H02J 50/60 20160201; Y02T 10/70 20130101; H02J 50/23
20160201; H03F 3/305 20130101; H02J 50/40 20160201; H03F 2200/102
20130101; H03F 2200/462 20130101; H03F 2203/30114 20130101; H02J
7/0044 20130101; B60L 2210/30 20130101; H01Q 1/273 20130101; H02J
50/27 20160201; Y02T 10/72 20130101; Y02T 90/14 20130101; H01Q 7/08
20130101; H03F 2200/09 20130101; H02J 50/80 20160201; B60L 2210/40
20130101; B60L 2210/10 20130101; H02J 7/00034 20200101; H03J
2200/06 20130101; H04B 5/0081 20130101; H03F 2200/387 20130101;
Y02T 10/7072 20130101; H02J 7/025 20130101; H03F 3/195 20130101;
H02J 50/70 20160201; H04B 5/0037 20130101; Y02T 90/12 20130101;
Y02T 10/90 20130101; H02J 50/20 20160201; H03F 1/56 20130101; H03L
7/0812 20130101; H02J 50/12 20160201; H02J 50/90 20160201; H03F
2203/30111 20130101 |
International
Class: |
H02J 50/12 20060101
H02J050/12; H02J 50/40 20060101 H02J050/40; H02J 50/90 20060101
H02J050/90; H02J 7/02 20060101 H02J007/02 |
Claims
1. (canceled)
2. A transmitter for wirelessly transmitting power, the transmitter
comprising: an antenna for creating an electric field, the antenna
comprising at least one conductor; a coil connected to the antenna;
and a resonator connected to the coil for resonating the coil and
the conductor at a resonant frequency, the resonator comprising a
tuning circuit having a sensor configured to sense an output at the
antenna, wherein the antenna receives a feedback signal based on
the sensed output.
3. The transmitter of claim 2, wherein the tuning circuit further
comprises: an oscillator configured to inject a start-up signal
into the tuning circuit via a switch.
4. The transmitter of claim 3, wherein the tuning circuit further
comprises: an envelope detector connected to the sensor and the
switch.
5. The transmitter of claim 4, wherein the switch is conditioned to
disconnect the tuning circuit from the oscillator after receiving a
signal from the envelope detector.
6. The transmitter of claim 2, wherein the tuning circuit further
comprises: a switch conditioned to isolate the antenna if the
sensed output exceeds a pre-determined safety tolerance.
7. The transmitter of claim 6, wherein the switch is conditioned to
isolate the transmitter from input power if the sensed output
exceeds the pre-determined safety tolerance.
8. The transmitter of claim 2, wherein the tuning circuit further
comprises: a delay line configured to delay a power signal to the
antenna.
9. The transmitter of claim 2, wherein the tuning circuit further
comprises: a balun configured to decouple the coil from ground.
10. The transmitter of claim 2, wherein the output is any one of an
output voltage and current at the antenna, an output current at the
antenna and a phase of an output current at the antenna.
11. The transmitter of claim 2, wherein the sensor is a
current-sensing toroid.
12. A method of tuning a transmitter for wirelessly transmitting
power, the method comprising: providing an antenna for creating an
electric field, the antenna connected to a coil, wherein the
antenna comprises at least one conductor; resonating the conductor
and the coil at a start-up frequency; and sensing an output at the
antenna.
13. The method of claim 12, further comprising: receiving a signal
at a switch connected to the antenna, the signal based on the
sensed output.
14. The method of claim 13, further comprising: disconnecting the
antenna from a source of the start-up frequency via the switch
after the switch receives the signal.
15. The method of claim 13, further comprising: disconnecting the
antenna from a power source to the antenna via the switch after the
switch receive the signal.
16. The method of claim 12, further comprising: processing the
sensed output.
17. The method of claim 16, further comprising: inputting the
processed output to the antenna
18. The method of claim 17, further comprising: delaying the
processed output prior to the inputting.
19. The method of claim 18, wherein the delaying is performed via a
delay line comprising inverters.
20. The method of claim 13, further comprising: detecting an
envelope of the sensed output.
21. The method of claim 20, wherein the detecting is performed via
an envelope detector.
22. The method of claim 20, further comprising: outputting the
envelope to the switch.
23. A wireless electric field power transmission system for
powering a load, the system comprising: a transmitter for
wirelessly transmitting power, the transmitter comprising: a
transmitter antenna for creating an electric field, the transmitter
antenna comprising at least one conductor; a transmitter coil
connected to the transmitter antenna; and a resonator connected to
the transmitter coil for resonating the transmitter coil and the
conductor of the transmitter antenna at a resonant frequency, the
resonator comprising a tuning circuit having a sensor configured to
sense an output at the transmitter antenna, wherein the antenna
receives a feedback signal based on the sensed output; and a
receiver for receiving wirelessly transmitted power from the
transmitter, the receiver comprising: a receiver antenna comprising
at least two conductor, the receiver antenna configured to receive
power from the transmitter antenna via resonant electric field
coupling; a receiver coil connected to the receiver antenna; and a
power harvester connected to the receiver coil, the power harvester
configured to extract power received by the receiver antenna.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This U.S. non-provisional patent application is a
continuation of U.S. application Ser. No. 13/607,474 filed on Sep.
7, 2012, which claims the benefit of U.S. Provisional Application
No. 61/532,092 filed on Sep. 7, 2011, the contents of each of which
are incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to wireless power
transmission and in particular, to a wireless electric field power
transmission system and method.
BACKGROUND OF THE INVENTION
[0003] A variety of radiative, or far-field, and non-radiative, or
near-field, energy or power transfer techniques are known. For
example, radiative wireless information transfer using
low-directionality antennas, such as those used in radio and
cellular communications systems and home computer networks, may be
considered wireless energy transfer. As will be appreciated, this
type of radiative energy transfer is inefficient because only a
small portion of the supplied or radiated power, namely, that
portion in the direction of, and overlapping with, the receiver is
picked up. The vast majority of the power is radiated in other
directions and lost in free space. Such inefficient energy transfer
may be acceptable for data transmission, but is not practical when
trying to transfer useful amounts of electrical energy for the
purpose of doing work, such as for example, powering or charging
electrical devices. One way to improve the transfer efficiency of
some radiative energy transfer schemes is to use directional
antennas to confine and preferentially direct a beam of radiated
energy towards a receiver. However, these directed radiation
schemes typically require an uninterruptible line-of-sight between
the transmitter and receiver as well as potentially complicated
tracking and steering mechanisms in the case of mobile transmitters
and/or receivers. In addition, such directed radiation schemes may
pose hazards to objects or people that cross or intersect the beam
of radiated energy when modest to high amounts of power are being
transmitted.
[0004] A known non-radiative, or near-field, wireless power
transmission system, often referred to as either induction or
traditional induction, does not (intentionally) radiate power, but
instead uses an oscillating current passing through a primary coil,
to generate an oscillating magnetic near-field that induces
currents in a near-by receiving or secondary coil. Induction
schemes of this nature have demonstrated the transmission of modest
to large amounts of power, however only over very short distances,
and with very small offset tolerances between the primary coil and
the secondary coil. Electric transformers and proximity chargers
are examples of devices that utilize this known short range,
near-field energy transfer scheme.
[0005] PCT Application Publication No. WO 2009/089146 discloses a
wireless power transmission system that includes a transmitter and
a receiver. The transmitter includes a radio frequency energy
generator, a first transmitting plate, and a second transmitting
plate. The first transmitting plate is operatively coupled to the
radio frequency energy generator. The second transmitting plate is
operatively coupled to a ground. The receiver includes a rectifier,
a first receiving plate, and a second receiving plate. The first
receiving plate is operatively coupled to the rectifier. The first
receiving plate is configured to be capacitively coupled to the
first transmitting plate and the second receiving plate is
configured to be capacitively coupled to the second transmitting
plate. The second receiving plate is operatively coupled to a
ground.
[0006] U.S. Patent Application Publication No. 20110198939
discloses embodiments of a transmitter that includes a
substantially two-dimensional high-Q resonator structure including
a flat coil and an impedance-matching structure operably connected
to the resonator structure. The transmitter is configured to
transmit power wirelessly to another high-Q resonator.
[0007] U.S. Patent Application Publication No. 20090206675
discloses a means for transporting electrical energy and/or
information from a distance by using, at a slowly varying regime,
the Coulomb field which surrounds any set of charged conductors. A
device is composed of energy production and consumption devices
situated a short distance apart, and it uses neither the
propagation of electromagnetic waves nor induction and cannot be
reduced to a simple arrangement of electrical capacitors. The
device is modeled in the form of an interaction between oscillating
asymmetric electric dipoles, consisting of a high-frequency
high-voltage generator (1) or of a high-frequency high-voltage load
(5) placed between two electrodes. The dipoles exert a mutual
influence on one another. The device is suitable for powering
industrial and domestic electrical apparatus and is especially
suitable for powering low-power devices moving in an environment
and for short-distance non-radiating transmission of
information.
[0008] Although wireless power transmission techniques are known,
improvements are desired. It is therefore an object of the present
invention to provide a novel wireless electric field power
transmission system and method.
SUMMARY OF THE INVENTION
[0009] Accordingly, in one aspect there is provided a wireless
electric field power transmission system comprising: a transmitter;
a transmitter antenna connected to the transmitter, the transmitter
antenna comprising at least two conductors defining a volume
therebetween; and at least one receiver, wherein the transmitter
antenna transfers power wirelessly via electric field coupling when
the at least one receiver is within the volume.
[0010] According to another aspect there is provided a method for
wirelessly transmitting power, the method comprising: oscillating a
transmitter antenna comprising at least two conductors defining a
volume at a transmitter resonant frequency; generating an electric
field in the volume; positioning a receiver antenna comprising two
plates in the volume; and oscillating the receiver antenna at the
transmitter resonant frequency.
[0011] According to yet another aspect there is provided a method
for wirelessly transferring power, the method comprising:
resonating a transmitter antenna comprising at least two conductors
and a transmitter coil at a start-up frequency; tuning the
transmitter antenna and the transmitter coil to their resonant
frequency; generating an electric field within a volume defined by
at least two conductors; placing a receiver with a receiver antenna
comprising two plates in the volume; accumulating a potential
difference on the two plates; resonating the receiver antenna at
the resonant frequency; and gathering power from the receiver
antenna.
[0012] According to yet another aspect there is provided a
transmitter for wirelessly transmitting power, the transmitter
comprising: an antenna for creating an electric field, the antenna
comprising at least two conductors defining a volume therebetween;
a coil connected to the antenna; and a resonator connected to the
coil for resonating the coil and the antenna at a resonant
frequency, the resonator comprising an auto frequency tuning
circuit for automatically tuning the resonator to the resonant
frequency.
[0013] The antenna may comprise at least two generally parallel
plates that are laterally spaced to define the volume.
[0014] The antenna may comprise six conductors defining the
volume.
[0015] The antenna may be a near-field antenna.
[0016] Each conductor may be formed of conductive tape.
[0017] The coil may be constructed using strand wire.
[0018] The coil may be a toroid spiral, cylindrical spiral, flat
spiral or pancake coil.
[0019] The auto frequency tuning circuit may further comprise
circuitry configured to boost a signal to the antenna. The
circuitry may comprise at least one of a voltage gain, a current
gain and a power amplifier. The power amplifier may be a push-pull
power amplifier.
[0020] The auto frequency tuning circuit may further comprise a
delay line configured to delay the signal within the auto frequency
tuning circuit. The delay line may be an active inverter delay
chain comprising complementary metal-oxide-semiconductor (CMOS)
inverters connected in series.
[0021] The auto frequency tuning circuit may further comprise a
decoupling circuit configured to decouple an output signal of the
transmitter. The decoupling circuit may comprise a balun.
[0022] The auto frequency tuning circuit may further comprise a
current sensing circuit configured to provide a feedback
signal.
[0023] The auto frequency tuning circuit may further comprise an
oscillator configured to inject a start-up signal into the auto
frequency tuning circuit.
[0024] The resonator may further comprise modification circuitry
configured to modify the output signal of the transmitter when a
condition occurs. The modification circuitry may adjust the power
level of the output signal when the condition occurs. The
modification circuitry may shut off output of the transmitter when
the condition occurs.
[0025] In one embodiment, there is provided a vehicle comprising
the transmitter of the present aspect.
[0026] In another embodiment, there is provided a table comprising
the transmitter of the present aspect.
[0027] In another embodiment, there is provided a container
comprising the transmitter of the present aspect. The container may
be shielded to prevent electromagnetic field (EMF) leakage.
Electric field strength may be increased when the container is
closed.
[0028] According to still yet another aspect there is provided a
receiver for receiving wirelessly transmitted power, the receiver
comprising: an antenna comprising two conductors; a coil connected
to the antenna; a resonator connected to the coil for resonating
the coil and the antenna at a resonant frequency, the resonator
comprising an auto frequency tuning circuit for automatically
tuning the resonator to the resonant frequency.
[0029] The conductors may be external to a housing accommodating
the coil and the resonator.
[0030] The conductors may be plates or rails. The rails may be
rectangular and parallel. The rails may be metallic.
[0031] The coil may be constructed of strand wire or inductors.
[0032] The coil may be a toroid, cylindrical spiral, flat spiral or
pancake coil.
[0033] The resonator may further comprise modification circuitry
configured to modify a signal received by the receiver when a
condition occurs. The modification circuitry may adjust the signal
received by the receiver when the condition occurs. The
modification circuitry may be a voltage converter and/or a
rectifier.
[0034] The receiver may further comprise an impedance matching
circuit. The impedance matching circuit may comprise a balun.
[0035] In one embodiment, there is provided a backpack for
receiving wirelessly transmitted power, the backpack comprising the
receiver of the present aspect. The backpack may further comprise a
battery charger connected to the receiver. The backpack may further
comprise at least one rechargeable battery connected to the
receiver configured to charge when no batteries are present in the
battery charger.
[0036] In another embodiment, there is provided a radio
communication device for receiving wirelessly transmitted power,
the device comprising the receiver of the present aspect.
[0037] In another embodiment, there is provided a computing device
for receiving wirelessly transmitted power, the device comprising
the receiver of the present aspect.
[0038] In another embodiment, there is provided a device comprising
the transmitter of the previous aspect, and the receiver of the
present aspect.
[0039] According to still yet another aspect there is provided a
wireless electric field power transmission system comprising: a
transmitter; a transmitter antenna connected to the transmitter,
the transmitter antenna comprising at least one conductor; and at
least one receiver, wherein the transmitter antenna transfers power
wirelessly via electric field coupling when the at least one
receiver is coupled to the transmitter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Embodiments will now be described more fully with reference
to the accompanying drawings in which:
[0041] FIG. 1 is a schematic layout view of a wireless electric
field power transmission system;
[0042] FIG. 2 is schematic layout view of a transmitter and
transmitter antenna forming part of the wireless electric field
power transmission system of FIG. 1;
[0043] FIG. 3a is a top plan view of a transmitter coil forming
part of the transmitter of FIG. 2;
[0044] FIG. 3b is a perspective view of another embodiment of the
transmitter coil of FIG. 3a;
[0045] FIG. 3c is a perspective view of another embodiment of the
transmitter coil of FIG. 3a;
[0046] FIG. 4 is a block diagram of a printed circuit board
accommodating components of the transmitter of FIG. 2;
[0047] FIG. 5a is a block diagram of components of the transmitter
of FIG. 2;
[0048] FIG. 5b is a circuit diagram of the components of FIG.
5a;
[0049] FIG. 6 is a circuit diagram of a power amplifier forming
part of the transmitter of FIG. 2;
[0050] FIG. 7 is a schematic layout view of a receiver forming part
of the wireless electric field power transmission system of FIG.
1;
[0051] FIG. 8 is a block diagram of a printed circuit board
accommodating components of the receiver of FIG. 7;
[0052] FIG. 9 is a circuit diagram of components of the receiver of
FIG. 7;
[0053] FIG. 10 is a circuit diagram of a rectifier forming part of
the receiver of FIG. 7;
[0054] FIG. 11a is a perspective view of a receiver coil forming
part of the receiver of FIG. 7;
[0055] FIG. 11b is a perspective view of another embodiment of the
receiver coil of FIG. 11a;
[0056] FIG. 11c is a top plan view of another embodiment of the
receiver coil of FIG. 11a;
[0057] FIG. 12 shows the intensity of an electric field generated
by the transmitter and transmitter antenna of FIG. 2;
[0058] FIG. 13 is a schematic layout view of another embodiment of
a transmitter and transmitter antenna for the wireless electric
field power transmission system of FIG. 1;
[0059] FIG. 14 shows the intensity of an electric field generated
by the transmitter and transmitter antenna of FIG. 13;
[0060] FIG. 15 is a schematic layout view of ferrite core
inductors;
[0061] FIG. 16 is a schematic layout view of another embodiment of
a receiver antenna;
[0062] FIG. 17 is a circuit diagram of components of an alternative
receiver;
[0063] FIGS. 18a and 18b are perspective views of a backpack
equipped with a receiver and receiver antenna;
[0064] FIGS. 19a and 19b are perspective views of a vehicle
equipped with a transmitter and transmitter antenna;
[0065] FIGS. 20a and 20b are perspective views of a radio equipped
with a receiver and receiver antenna;
[0066] FIGS. 21a and 21b are perspective views of a fire truck
equipped with a transmitter and transmitter antenna;
[0067] FIGS. 22a and 22b are perspective views of a tent equipped
with a transmitter and transmitter antenna;
[0068] FIGS. 23a and 23b are perspective views of a bus cargo
interior equipped with a transmitter and transmitter antenna;
[0069] FIGS. 24a and 24b are perspective views of an airplane
interior equipped with a transmitter and transmitter antenna;
[0070] FIGS. 25a and 25b are perspective views of a table equipped
with a transmitter and transmitter antenna;
[0071] FIGS. 26a, 26b, 26c and 26d are perspective views of a
laptop computer equipped with a receiver and receiver antenna;
[0072] FIGS. 27a and 27b are perspective views of a tablet computer
equipped with a receiver and receiver antenna;
[0073] FIGS. 28a and 28b are perspective views of a container
equipped with a transmitter and transmitter antenna;
[0074] FIGS. 29a and 29b are perspective views of a tabletop
equipped with a transmitter and transmitter antenna;
[0075] FIGS. 30a and 30b are perspective views of a cellular phone
equipped with a receiver and receiver antenna;
[0076] FIGS. 31a and 31b are perspective views of a television set
equipped with a receiver and receiver antenna;
[0077] FIGS. 32a and 32b are perspective views of a battery
equipped with a receiver and receiver antenna;
[0078] FIGS. 33a and 33b are perspective views of a vehicle
equipped with a receiver and receiver antenna;
[0079] FIGS. 34a and 34b are perspective views of a military
vehicle equipped with a transmitter and transmitter antenna;
and
[0080] FIGS. 35a and 35b are perspective views of an Unmanned
Autonomous Vehicle (UAV) equipped with a receiver and receiver
antenna.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0081] Turning now to FIG. 1, a wireless electric field power
transmission system is shown and is generally identified by
reference numeral 10. As can be seen, power transmission system 10
comprises a transmitter 12 comprising a transmitter antenna 16
coupled and a plurality of receivers 14. Although only two
receivers 14 are shown, it will be appreciated that this is for
ease of illustration only. The power transmission system 10 may
comprise more or fewer receivers 14. The transmitter antenna 16
comprises two approximately parallel, laterally spaced conductors
18 defining a volume 20 between them. The conductors 18 are
elongate and generally rectangular and are oriented such that major
surfaces of the conductors face one another. In this embodiment,
each conductor 18 is formed of aluminum foil tape due to its
flexibility, low cost and availability. Each receiver 14 can be
positioned within the volume 20 to harvest power wirelessly as a
result of an electric field generated within the volume 20 by the
transmitter antenna 16.
[0082] Turning now to FIG. 2, the transmitter 12 comprising the
transmitter antenna 16 are better illustrated. The transmitter 12
further comprises a transmitter coil 30 and a resonator 32
connected to the transmitter coil 30 for resonating the coil 30 and
the transmitter antenna 16 at a resonant frequency. The components
of the resonator 32 are mounted on a printed circuit board (PCB) or
other suitable substrate. A transmitter case or housing 34 houses
the transmitter coil 30 and the resonator 32.
[0083] In this embodiment, the transmitter coil 30 is a flat spiral
or pancake coil as seen in FIG. 3a and is constructed using 14 AWG
(American Wire Gauge) insulated solid copper wire. The transmitter
coil 30 has forty-eight (48) turns and a diameter of approximately
fifteen (15) inches (37.5 cm). The operating frequency of the
transmitter coil 30 is one (1) MHz and the inductance of the
transmitter coil is two hundred and eighty (280) uH. The
transmitter coil 30 has a quality factor (Q-factor) of two hundred
(200). The transmitter coil 30 is configured to create a high
Q-factor resonance with the conductors 18 of the transmitter
antenna 16 at its operating frequency.
[0084] Turning now to FIG. 4, the resonator 32 is better
illustrated. As can be seen, the resonator 32 in this embodiment
comprises a power amplifier 36, a safety shut-off circuit 38, a
power board 40, an automatic gain control (AGC) circuit 42, an auto
frequency tuning (AFT) circuit 44 and a phase detector 46. The
power amplifier 36, AFT circuit 44 and phase detector 46 are
further illustrated in FIG. 5a. These components are configured to
automatically detect and tune to the frequency of power transmitted
by the transmitter antenna 16 to enhance or optimize wireless
electric field power transfer to receivers 14 positioned within the
volume 20 as will be described. The circuitry comprises a delay
line 41, a current gain stage 43 and a voltage gain stage 45
connected in series. The voltage gain stage 45 is connected to the
power amplifier 36. A decoupling circuit in the form of a balun 48
is connected between the power amplifier 36 and the transmitter
coil 30 to decouple the power amplifier output from ground. A
current sensor in the form of a current sensing toroid 49 senses
the current output by the balun 48. The current sensing toroid 49
and the current gain stage 43 provide output to a feedback and
control circuit 47.
[0085] As shown in FIG. 5b, the delay line 41 is implemented using
an active inverter delay chain 502 that receives input from a
start-up oscillator 504 via a normally closed semiconductor switch
506. The inverter delay chain 502 comprises a plurality of
complementary metal-oxide-semiconductor (CMOS) inverters 508
connected in series. The inverter delay chain 502 is connected to
the current gain stage 43 which comprises a plurality of current
boosting inverting stages 510 arranged in parallel. In this
embodiment, the current gain stage 43 comprises three (3) inverting
stages 510. The last inverting stage 510 comprises forty (40) CMOS
inverters 510a, the middle inverting stage 510 comprises twelve
(12) CMOS inverters 510a and the first inverting stage 510
comprises four (4) CMOS inverters 510a. The outputs of the
inverters 510a of the last inverting stage 510 are coupled and
connected to the voltage gain stage 45 which in this embodiment is
a wideband transformer 512. The wideband transformer 512 has a turn
ratio of 1:4. The last inverting stage 510 of the current gain
stage 43 is connected to one coil of the wideband transformer 512.
The other coil of the wideband transformer 512 is connected to the
power amplifier 36. The output of the power amplifier 36 is coupled
to one coil of the balun 48. The balun 48 in this embodiment has a
ferrite core and a turn ratio of slightly higher than 1:1 for
impedance matching purposes. The ferrite core balun has been found
to provide twice as much current as an air balun and greater
efficiency. The other coil of the balun 48 provides balanced
differential output ports. One output port of the balun 48 is
connected to the transmitter coil 30 via a tuning capacitor 518.
The other output port of the balun 48 passes through the current
sensing toroid 49 and is connected to the transmitter antenna
16.
[0086] The current sensing toroid 49 provides a feedback signal to
the active inverter delay chain 502 as part of the feedback and
control circuit 47 via an RC network 516 and to the phase detector
46 via the RC network 516 and an inverter 518a. Phase detector 46
also receives the output of the current gain stage 43 via an
inverter 518b. Phase detector 46 functions with a charge pump 520
to keep the start-up oscillator 504 in phase and frequency lock.
The current sensing toroid 49 also provides the feedback signal to
an envelope detector 522 via the RC network 516 which in turn
provides output to the normally closed semiconductor switch
506.
[0087] The power amplifier 36 in this embodiment, as shown in FIG.
6, is a class-AB push-pull power amplifier and is used to increase
the signal input thereto by a factor of at least eighty (80)
(approximately nineteen (19) dB), which is then delivered to the
transmitter coil 30 via the balun 48.
[0088] The safety shut-off circuit 38 is an automatic shut-off
circuit that determines when people, animals or other living
organisms are present in the volume 20 and reduces the strength of
or stops power transmitted by the transmitter antenna 16. The
safety shut-off circuit 38 also shuts off power to the transmitter
12 in the event of an overload caused by shorting, thermal runaway
or any other such occurrence. In this embodiment, the safety
shut-off circuit 38 is implemented using an operational amplifier
(Op-amp) (not shown), a semiconductor switch (not shown) in the
form of a metal-oxide-semi-conductor field-effect transistor
(MOSFET) and an envelope detector (not shown). The envelope
detector monitors the output of the transmitter 12 and sends a
signal to the Op-amp when a sudden change in output current or
voltage is detected. The Op-amp in response transmits a signal to
the semiconductor switch which shuts down the resonator 32 by
isolating the resonator from input power.
[0089] The power board 40 comprises a plurality of high efficiency
voltage regulators (not shown) that convert conventional AC mains
power into DC power that is used to power the various components of
the transmitter 12.
[0090] The AGC circuit 42 is used in conjunction with the power
amplifier 36 to control the output power transmitted. The AGC
circuit 42 is a radio frequency (RF) circuit having absolute values
of power which are dependent on the required level of safety. In
this embodiment, the AGC circuit 42 is implemented using an Op-amp
(not shown), a semiconductor switch (not shown) in the form of a
MOSFET and an envelope detector (not shown). The envelope detector
monitors the output of the transmitter 12 and when the output
exceeds a threshold value, sends a signal to the Op-amp. The Op-amp
in response sends an appropriate signal to the semiconductor switch
causing the semiconductor switch to limit the power output of the
power amplifier 36.
[0091] Turning now to FIG. 7, one of the receivers 14 is better
illustrated. As can be seen, receiver 14 comprises a high Q-factor
receiver coil 52, a receiver antenna 54 that is connected to the
receiver coil 52 and a power harvester 50 connected to the receiver
coil 52. The components of the power harvester 50 are mounted on a
printed circuit board (PCB) or other suitable substrate. The
receiver antenna 54, receiver coil 52 and power harvester 50 are
accommodated by a receiver case or housing 56. The power harvester
50 includes connectors and jacks from which received power is
output. Devices requiring power can be connected to these
connectors and jacks.
[0092] FIG. 8 better illustrates the power harvester 50. As can be
seen, power harvester comprises a receiver auto frequency tuning
(AFT) circuit 60, a receiver safety circuit 62, a bridge rectifier
64, a DC-DC voltage converter 66 and a receiver power supply (not
pictured). The AFT circuit 60 is similar to the transmitter AFT
circuit 32 shown in FIG. 5b and is configured to resonate the
receiver antenna 54 and coil 52. The receiver power supply powers
the AFT 60 circuit. A portion of the circuit layout of the power
harvester 50 is shown in FIG. 9. The device connected to the
receiver 14 is modeled as an inductor L.sub.p in series with a
resistor R.sub.p which are both in parallel with a capacitor
C.sub.p. The DC-DC voltage converter 66 is not shown in FIG. 9.
[0093] The output voltage across the high Q-factor resonant
receiver coil 52 results in an AC voltage. The voltage is rectified
by the bridge rectifier 64 which is connected to an output of the
receiver coil 52. The bridge rectifier 64 is shown in FIG. 10 and
converts the received AC voltage to a DC voltage which is in the
order of kilovolts. The bridge rectifier 64 employs ultra-fast
diodes D.sub.1 to D.sub.4 that have a low junction capacitance, a
high reverse breakdown voltage and low forward voltage drop.
[0094] The DC-DC voltage converter 66 has a high conversion ratio
and performs a DC-DC down-conversion to reduce the rectified
voltage output by the bridge rectifier 64 to useable levels. For
example, if a 0.5 W high AC signal is rectified by the bridge
rectifier 64, it will have a four hundred (400) V potential and one
(1) mA of current. Down-converting this rectified output voltage to
a more useable form such as for example, a five (5) V and eighty
(80) mA output is beneficial in particular applications. In this
embodiment, the maximum input voltage of the DC-DC voltage
converter 66 is greater than one thousand (1000) V while the output
voltage is between five (5) V and fourteen (14) V with a power
rating of one (1) W to four (4) W. The output of the bridge
rectifier 64 is connected to the DC-DC voltage converter 66 (not
shown) which then outputs the converted power to the device
requiring power through jacks and connectors.
[0095] The receiver safety circuit 62 automatically shuts off the
receiver 14 if an electric field is detected that is higher than
the standard safety limits. The receiver safety circuit 62 also
disables DC power to any device connected to the receiver 14 if a
short circuit load is detected.
[0096] The receiver antenna 54 in this embodiment comprises two
generally rectangular, approximately parallel conductors which in
this embodiment are conductive plates 58. The distance between the
two plates 58 is approximately equal to the average dimension of
each plate 58. The plates 58 may either be rigid or flexible. The
receiver antenna 54 has a low capacitance (approximately seven (7)
pF to nine (9) pF relative to its dimension and the received signal
wavelength. When resonant, the power harvester 50 harvests
electrical power through the electric field created within the
volume 20 between the conductors 18 of the transmitter antenna 16.
As will be appreciated, the receiver 14 is small relative to the
amount of power it can harvest within the volume 20.
[0097] The receiver coil 52 in this embodiment is a cylindrical
spiral coil as illustrated in FIG. 11a. The receiver coil 52 is
constructed of insulated, solid copper wire and has a diameter of
approximately four (4) inches (twelve (12) cm). The receiver coil
52 is positioned adjacent to the two plates 58.
[0098] In general, during operation the transmitter 12 is operated
so that it drives the transmitter antenna 16 causing an electric
field to be generated within the volume 20 between the conductors
18 by running opposite phase, equal magnitude currents through the
conductors 18. When a receiver 14 is positioned within the volume
20, the receiver antenna 54 begins to oscillate at the resonant
frequency resulting in wireless power being transmitted from the
transmitter 12 to the receiver 14 via electric field coupling.
[0099] The closed-loop architecture of the transmitter 12 ensures
the transmitter 12 automatically oscillates at the resonant
frequency of the transmitter antenna-transmitter coil pair at all
times. In particular, initially the start-up oscillator 504 is used
to inject a start-up signal that is applied to the inverter delay
chain 502 of the delay signal line 41. The current level of the
signal is then boosted by the current gain stage 43 and applied to
the power amplifier 36 via the wideband transformer 512 of the
voltage gain stage 45. The output of the power amplifier 36 is then
applied to the balun 48 which decouples the signal from ground and
provides output to the transmitting coil 30 via the tuning
capacitor 518. The transmitting coil 30 in turn drives the
transmitter antenna 16 resulting in the electric field being
generated within the volume 20. The feedback signal output by the
current sensing toroid 49, which senses the current in the
transmitter antenna 16, is used by the envelope detector 520 to
condition the semiconductor switch 520 to isolate the start-up
oscillator 504 from the inverter delay chain 502. As a result, the
feedback signal that is applied to the inverter delay chain 502 is
used to sustain the transmitter output. As will be appreciated, by
generating the feedback signal using the current sensing toroid 49
that senses the current running through the transmitter antenna 16
and feeding the signal back into the transmitter 12, the
transmitter 12 automatically oscillates at the resonant frequency
of the transmitter antenna-transmitter coil pair.
[0100] As will be appreciated, the transmitter 12 has a fast
self-tuning and compact design. Because the transmitter 12
automatically oscillates at the resonant frequency of the
transmitter antenna-transmitter coil pair, the transmitter antenna
16 stays tuned and does not require hand tuning or automatic tuning
circuitry. Also, the transmitter 12 does not require a
pre-amplifier or a digital control system to perform automatic
frequency tuning.
[0101] As mentioned above, when the transmitter coil 30 drives the
transmitter antenna 16, the electric field (a reactive near field)
is created within the volume 20 which can be used by each receiver
14 positioned within the volume to harvest power. An exemplary
electric field generated within the volume 20 is shown in FIG. 12.
As can be seen, the intensity of the electric field increases
towards the conductors 18 and weakens towards the middle of the
volume 20. Greater efficiency wireless power transfer to a receiver
14 is therefore achieved when the receiver is closer to the
conductors 18 and lower efficiency wireless power transfer to the
receiver 14 is achieved when the receiver is positioned near the
center of the volume 20. Thus, the power radiated is determined by
the separation between conductors 18 rather than conductor
length.
[0102] The high Q-factor of the transmitter 12 limits the amount of
power that an unintentional sink (such a human body within the
volume) can recover from the transmitter 12. When an unintentional
sink enters the volume 20, the generated electric field is no
longer resonant with the receiver 14, due to the sink disrupting
the resonance, causing a drop in the power of the electric field
such that the total power dissipated into the sink is less than
regulatory limits, in the case of a human body.
[0103] When a receiver 14 is positioned within the volume and the
electric field is present, a voltage is observed across the plates
58 of the receiver antenna 54 as a result of electric charge
accumulation on the two plates 58. The resonating of the receiver
antenna 54 by the AFT circuit 60 allows power to be harvested. In
particular, when the receiver antenna 54 is made resonant by the
AFT circuit 60, the amount of charge flowing from one plate 58 to
the other plate 58 is multiplied by the resonance Q-factor,
resulting in a high frequency AC signal that is converted to a DC
signal via the rectifier 64. The DC signal is then down-converted
by the DC-DC voltage converter 66 to a desired voltage and current
depending on the application. The signal output by the DC-DC
voltage converter is then received by the device modeled by the RLC
circuit (R.sub.p, L.sub.p and C.sub.p).
[0104] The output power of the receiver 14 depends on the strength
of the electric field available at the receiver 14, the distance
between the two plates 58 of the receiver antenna 54, and the
Q-factor of the receiver coil 52.
[0105] The strength of the electric field available at the receiver
14 changes depending on the position of the receiver 14 relative to
the conductors 18. As previously stated, the electric field is
weakest at the midpoint of the volume 20 between the two conductors
18. The receiver antenna 54 emits very small amounts of radiation
and almost all the electric field created by the transmitter
antenna 16 is reactive (i.e. non-radiating). Thus, large amounts of
power can be wirelessly transmitted to the receiver 14 without
violating electric field emission limits in the respective
frequency bands. Field emission limits in Canada can be found in
the Health Canada safety code 6 and field emission limits in the
U.S. can be found in IEEE standard C95.1-2005.
[0106] The wireless power harvesting efficiency is affected by the
orientation of the plates 58 relative to the electric field within
the volume 20. Since the electric field varies with distance,
having the two plates 58 separated by a distance along the electric
field direction (i.e. the common axis of the two plates 58 is along
the direction of the electric field) creates a potential difference
between the plates 58 when they are placed within the electric
field. When the common axis of the two plates 58 is perpendicular
to the direction of the electric field, the two plates 58 are
almost at the same potential which will significantly reduce the
efficiency of the power transfer. Thus, the wireless power
receiving efficiency depends on the length-to-distance ratio of the
two plates 58 and the orientation of the plates 58 relative to the
direction of the electric field. As will be appreciated,
maintaining the plates 58 normal to the electric field maximizes
the wireless power harvesting efficiency. Furthermore, the
orientation and location of the plates 58 relative to the electric
field determines the type of electric field coupling. The receiver
14 and transmitter 12 can be strongly, loosely or critically
coupled. When the receiver 14 is close to the transmitter 12 and
the plates 58 of the receiver 14 are aligned for maximum power
transfer at the highest efficiency level, the receiver 14 and
transmitter 14 are strongly coupled. When the receiver 14 is
farther away from the transmitter 12 and the plates 58 of the
receiver 14 are still aligned for maximum power transfer, the
receiver 14 and transmitter 12 are loosely coupled. The transmitter
12 and receiver 14 become critically coupled, when the receiver 14
is at a distance from the transmitter 12 where the efficiency level
of power harvesting falls below a threshold level and/or when the
orientation of the plates 58 relative to the electric filed is such
that the efficiency level of power harvesting falls below a
threshold level.
[0107] Wireless power transmission between the transmitter 12 and
the receiver 14 is based upon the resonant frequency of the
receiver antenna 54 and the receiver coil 52 being in tune with the
resonant frequency of transmitter antenna 16 and the transmitter
coil 30. Since the frequency can be affected by the environment in
which the volume 20 is located, the receiver AFT circuit 60 tunes
the operating frequency of the receiver 14 to the resonant
frequency required. The receiver AFT circuit 60 does not have to be
continuously active. It need only intermittently adjust the
operating frequency of the receiver 14 in response to environmental
changes in the volume 20. The receiver 14 must initially power the
receiver AFT circuit 60 with the receiver power supply, but once
wireless power transfer has commenced, the wirelessly transferred
power can be used to power the receiver AFT circuit 60. The
resonant frequency is initially known so that the receiver AFT
circuit 60 may tune the receiver 14 to this frequency.
[0108] Although an exemplary power transmission system has been
described above, those of skill in the art will appreciate that
many alternative configurations are possible. For example, if
desired the resonator 32 may comprise its own power source or
supply to supply power to the various components of the transmitter
12.
[0109] Although the transmitter coil 30 has been described as being
a flat spiral or pancake coil, different transmitter coils may be
used. For example, in another embodiment, the transmitter coil 30
is constructed using multiple strand Litz wire. Litz wire provides
increased overall efficiency relative to solid copper wire. In this
embodiment, the Litz wire is one hundred seventy-six (176) strand
forty (40) AWG wire and the resulting transmitter coil 30 has
thirty (30) turns with a diameter of approximately ten (10) inches.
The operating frequency of the transmitter coil is one (1) MHz and
the inductance of the transmitter coil is one hundred fifty (150)
uH. Such a transmitter coil 30 has a Q-factor of two hundred (200).
In yet another embodiment, the transmitter coil 30 is constructed
using multiple strand 48 AWG Litz wire. In this embodiment, the
Litz wire is 2700 strand and the resulting transmitter coil 30 has
forty-eight (48) turns with a diameter of approximately 15 inches.
The operating frequency of the transmitter coil is 1 MHz and the
inductance of the transmitter coil is 180 uH. Of course, those of
skill in the art will appreciate that variations in the number of
turns, gauge, number of strands, wire type are possible so long the
as transmitter coil 30 is resonant at the required frequency.
[0110] The transmitter coil may also take different shapes. For
example, FIG. 3b shows a toroidal transmitter coil 30 and FIG. 3c
shows a cylindrical spiral transmitter coil that may be employed
instead of the flat spiral or pancake coil.
[0111] The number and configuration of the conductors 18 of the
transmitter antenna 16 may also be varied. For example, FIG. 13
shows a transmitter antenna 16 with six conductors 18, three (3)
conductors of which are positioned on each side of the volume. In
this embodiment, the capacitive reactance is reduced, compared to
using two conductors 18. Similar to the previous embodiment, the
six conductors 18 are made of aluminum foil tape. The distribution
of the electric field that is emitted by the transmitter antenna
becomes more uniform due to the increase in the overall surface
area of the conductors 18. The electric field intensity decreases
near the sides and increase towards the middle of the volume 20 as
shown in FIG. 14 resulting in a more evenly distributed field. In
this embodiment, the conductors 18 of the transmitter antenna 16
are placed five (5) meters apart, however the separation distance
can be varied based on the application. For example, the conductors
18 may be installed in different room sizes, such that the
separation distance varies. In yet another embodiment, the
transmitter antenna 16 may comprise a single conductor 18.
[0112] The conductor material has been found to have little effect
on performance and as a result other conductive materials for the
conductors may be used. For example, the conductors 18 may be
formed of copper tape or other suitable conductive material. The
conductors 18 may also be covered with a decoration for aesthetic
purposes.
[0113] Although a particular implementation of the resonator
circuitry has been shown, this may also vary. For example, the
delay line 41 may be implemented using passive LC networks or
transmission lines. A non-ferrite core balun or other suitable
decoupling structure may be employed.
[0114] While a particular receiver 14 configuration has been
described, other configurations are possible. For example, the
plates 58 of the receiver antenna 54 need not be accommodated by
the receiver case 56, but rather may be external to the receiver
case 56.
[0115] Furthermore, the receiver coil 52 used may also vary. For
example, the receiver coil 52 may be constructed of Litz wire. In
one such embodiment, the Litz wire is forty (40) AWG, 3 strand Litz
wire. The resulting receiver coil 52 has over three-hundred (300)
turns and a Q-factor of sixty (60). The operating frequency of the
receiver coil is one (1) to two (2) MHz and the inductance of the
receiver coil is three (3) mH. The diameter of the receiver coil 52
is approximately four (4) inches (twelve (12) cm). The receiver
coil 58 is positioned between the two plates 58 and in this
orientation the magnetic field created by the receiver coil 52
creates lossy circular currents in the plates 58 which will
therefore dissipate a small amount of available power at the
receiver 14. In another embodiment, the wire (Litz wire or
insulated solid copper wire) used to make the receiver coil 52 may
be wound about a non-conducting material to ensure consistency of
the turns of the receiver coil 52. In another embodiment, Litz wire
that is forty-eight (48) AWG, fifty (50) strand Litz wire is used
for the receiver coil 52. The number of turns is over three hundred
(300), the frequency is one (1) MHz and the inductance is three (3)
mH. The diameter of the receiver coil 52 is still four (4) inches
(twelve (12) cm). In another embodiment, Litz wire that is
forty-eight (48) AWG, six hundred seventy-five (675) strand Litz
wire is used for the receiver coil. The number of turns is over
seventy-five (75), the frequency is two (2) MHz and the inductance
is seven hundred fifty (750) uH. The diameter of the receiver coil
52 is still four (4) inches (twelve (12) cm). Of course, those of
skill in the art will appreciate that variations in the number of
turns, gauge, number of strands, wire type are possible so long the
as receiver coil 52 is resonant at the required frequency.
[0116] In another embodiment, the receiver coil 52 is replaced with
ferrite-core inductors 70 as illustrated in FIG. 15. The inductors
70 are ten (10) millimeters long each and thus, smaller than the
receiver coil 52. The Q-factor for the set of small inductors 70 is
sixty (60) and the frequency is two (2) MHz. The inductors 70 are
designed to work at higher frequencies, have a high quality factor
and a high value of inductance, greater than fifty (50) uH.
[0117] The shape of the receiver coil may also be varied. For
example, FIG. 11b shows a toroidal receiver coil 52 and FIG. 11c
shows a flat spiral receiver coil.
[0118] In another embodiment, the receiver antenna 54 comprises
rails 68 instead of plates 58. The rails 68 are attached to a
substance with a low dielectric constant and positioned in the same
plane as illustrated in FIG. 16. Thus, the receiver antenna 54 can
be entirely flat allowing for easy incorporation into devices. The
rails 68 need not be precisely parallel to one and other.
[0119] While a particular configuration has been presented for the
DC-DC voltage converter 66, other configurations are possible. For
example, two or more DC-DC voltage converters 66 arranged in
parallel may be employed to down-convert the DC voltage output by
the rectifier to useable levels. Alternatively, two or more DC-DC
voltage converters 66 arranged in series may be employed to
down-convert the DC voltage output by the rectifier to useable
levels. For example, a first DC-DC converter may be employed to
convert the DC voltage output by the rectifier from one thousand
(1000) V to one hundred (100) V then a second DC-DC converter 66
may be employed to convert the DC voltage output by the first DC-DC
converter from one hundred (100) V to five (5) V. The overall
efficiency of the entire down-conversion will be the product of all
the blocks connected in series which is lower than just one of the
converters 66.
[0120] Furthermore, while particular power harvesting circuitry has
been described with reference to FIG. 9, other configurations are
possible. For example, in another embodiment, the circuitry of FIG.
9 has a series configuration. As shown in FIG. 17, the device is
connected to the bridge rectifier 64 in series. The device is
modeled by an inductor L.sub.s, capacitor C.sub.s and resister
R.sub.s which are connected in series which results in lower output
AC voltages and higher currents compared to the parallel
configuration. A balun is placed between the L.sub.sC.sub.s series
resonant circuit and bridge rectifier 64 to provide impedance
matching.
[0121] In another embodiment, the impedance is matched in the
receiver 14 using lumped element matching.
[0122] The power transmission system may be employed in a variety
of diverse applications to allow power to be wirelessly transmitted
from the transmitter to the receiver via electric field coupling.
For example, in one application the receiver 14 is positioned
within a backpack 100 as shown in FIGS. 18a and 18b. The plates 58
are integrated into the backpack 100 on opposite sides thereof. The
plates 58 are connected to the receiver case 56 and the components
within the receiver case 56. The receiver case 56 is then further
connected (not shown) to a recharger that recharges traditional
batteries such as AA, 9V batteries or other non-traditional or
custom rechargeable battery formats. The backpack 100 may be used
in military applications where soldiers require batteries for a
variety of equipment, such as night-vision goggles. Recharging
batteries reduces the need for backup batteries to be carried by
the soldiers thereby reducing the already significant weight of
backpacks 100 used in the military. The backpack 100 may further
comprise a battery (not shown) connected to the receiver 14 that
charges when no batteries are present in the recharger.
[0123] The transmitter 12 and transmitting antenna 16 may be
integrated into a vehicle 102 as illustrated in FIGS. 19a and 19b.
In this example, the conductors 18 of the transmitter antenna 16
are integrated into the interior walls of the vehicle 102 and
hidden and are connected to the transmitter 12. The conductors 18
are positioned such that they are approximately parallel to each
other. When backpacks 100 are placed in the vehicle 102 and within
the volume between the conductors, the receivers 14 are able to
harvest power in the manner described above.
[0124] In another application, the receiver 14 is integrated into a
radio communication device 104 such as those used by firefighters,
police officers or other individuals. As will be appreciated, in
instances the radio communication devices 104 may not be fully
charged either due to neglect or insufficient preparation time
before an emergency situation. In this case, the rails 68 of the
receiver 14 are affixed to the backside of the radio communication
device 104 as shown in FIGS. 20a and 20b. The transmitter 12 and
transmitter antenna may be integrated into the front cabin of a
fire truck or other vehicle 106 as shown in FIGS. 21a and 21b.
Thus, when radio communication devices are placed inside the front
cabin of the fire truck 106 and within the volume between the
conductors 18 of the transmitter antenna, the radio communication
devices are charged. In another embodiment, the transmitter and
transmitter antenna are placed at a particular location within a
fire station.
[0125] In another application, the power transmission system 10 may
be employed in a military base camp. When military officers set up
a base camp most of the electronic equipment is stored in a few
select tents 108 or barracks as shown in FIGS. 22a and 22b. This is
in part due to the fact that not every location is equipped with
electricity to power the electronic equipment. In this embodiment,
the conductors 18 of the transmitter antenna 12 are integrated into
the interior walls of the tent 108 and provide wireless power to
all devices within the tent 108 which are equipped with a receiver
14. Tables that support the devices, are positioned near the tent
108 interior walls, thus near the conductors 18, ensuring maximum
power transfer efficiency. The devices can therefore be charged
without requiring physical corded connections reducing the large
number of hazardous wires and power cables.
[0126] In another application, the transmitter 12 and transmitter
antenna are integrated into the interior of a bus cargo area 110 as
illustrated in FIGS. 23a and 23b. The conductors 18 are integrated
into opposite walls of the interior of the bus cargo area 110 and
transmit power wirelessly to backpacks 100, or other devices
equipped with receivers 14, when they are placed within the cargo
area 110.
[0127] In another application, the transmitter 12 and the
transmitter antenna 16 are integrated into the interior of an
airplane 112 as illustrated in FIGS. 24a and 24b. The conductors 18
of the antenna 16 are integrated into the interior walls of the
airplane 112. Backpacks 100 or other devices equipped with receiver
power wirelessly when situated within the plane 112 interior.
[0128] In another application the transmitter 12 and transmitter
antenna 16 are integrated into a table 114 as illustrated in FIGS.
25a and 25b. The conductors 18 are flat on the table 114 and
connected to the transmitter coil 30 as already explained. The
receiver 14 is situated on, above or between the conductors 18 to
receive power wirelessly.
[0129] In another application the plates 58 of the receiver 14 are
affixed to a laptop computer 116 as illustrated in FIGS. 26a and
26b. One plate 58 is flat and affixed to the laptop computer 116
behind the display screen, while the other plate 58 is flat and
affixed below the keyboard on the bottom of the laptop computer
116. The received wireless power can be transferred to the battery
of the laptop computer 116.
[0130] In another application the rails 68 of the receiver 14 are
in the same plane, both on the back of the screen or both on the
bottom of the laptop computer 116 as illustrated in FIGS. 26c and
26d. This configuration is well suited to receive power from the
table 114 equipped with a transmitter 12 as already described.
[0131] In another application the plates 58 of the receiver 14 are
mounted some distance away from each other on the backside of the
screen of a tablet computer 118 similar to the mounting on the back
of a laptop screen already described as illustrated in FIGS. 27a
and 27b.
[0132] In another application the transmitter 12 and transmitter
antenna are integrated into an enclosed container 120, which may
have one or more removable or hinged panels to allow for receiver
14 devices to be placed inside as illustrated in FIGS. 28a and 28b.
When receivers 14 are inside the container 120, they can receive
wireless power transmitted from the transmitter 12. The container
120 may be constructed such that it is shielded to prevent any
leakage of the electromagnetic field (EMF) or other signals or
fields from the inside of the container 120 to the outside. When
the panels or lid of the container 120 is closed, the transmitter
12 is made aware via a signal that the signal or field strength
inside the container 120 can be increased without risk of exposure
to humans or animals, thereby allowing greater amounts of power and
higher rates of power transfer efficiency to be achieved. This
allows for faster rates of battery recharging from receivers 14
inside the container 120 when it is closed or sealed.
[0133] In another application the transmitter 12 and transmitter
antenna 16 are integrated into, laid upon or otherwise affixed to a
flat surface upon which receiver 14 devices may be laid or hung.
This can include, but is not limited to, tables, desks, counters,
shelves, walls, floors, ceilings, and doors. Integration of the
conductors 18 of the transmitter 12 into a tabletop 122 is
illustrated in FIGS. 29a and 29b.
[0134] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to a cordless, mobile or
cellular phone 124 as illustrated in FIGS. 30a and 30b.
[0135] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to a television set 126,
whether the television is Plasma, LCD, LED, OLED or of some other
technology as illustrated in FIGS. 31a and 31b.
[0136] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to a home electronics
devices including, but not limited to, DVD players, Blu-ray
players, receivers, amplifiers, all-in-one home theatre, speakers,
sub-woofers, video game consoles, video game controllers, remote
control devices, televisions, computers or other monitors, digital
cameras, video cameras, digital photo frames, video or image
projectors or media streaming devices.
[0137] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to rechargeable batteries
128 such that the battery becomes a receiver device as illustrated
in FIGS. 32a and 32b.
[0138] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to an electric or hybrid
motorized vehicle 130. In this embodiment the plates 58 are located
on the bottom of the vehicle 130 for receiving wireless power from
a transmitter 12 placed below the vehicle 130 as illustrated in
FIGS. 33a and 33b. The transmitter 12 and transmitter antenna 16
may be placed in a mat under the vehicle 130, or embedded in or
below the road or driveway under the vehicle 130.
[0139] In another application the transmitter 12 and transmitter
antenna 16 are integrated into fold-out flaps or barriers that are
attached to a military vehicle 132, walls, or doors as illustrated
in FIGS. 34a and 34b. When such flaps are extended from the
structure or device onto which they are mounted, they create a
volume 20 within which receivers 14 may be placed for wireless
power transfer. The flaps may incorporate hooks, shelves or other
such devices for holding or otherwise mounting structures including
receivers 14, such as backpacks.
[0140] In another application the plates 58 of the receiver 14 are
integrated into or are otherwise affixed to an Unmanned Autonomous
Vehicles (UAVs) 134 or other such vehicles or devices, such that
wireless power may be delivered to the UAV and its onboard power
system and/or power storage device as illustrated in FIGS. 35a and
35b.
[0141] In another application the transmitter 12 and transmitter
antenna 16 are integrated into a device that may be located in a
public space or common area, whereby one or more people may enter
the transmission volume 20 and receive wireless power with their
own device comprising at least one receiver 14. These publicly
available zones for wireless power transmission may be referred to
as HotSpots, as they are for publicly available wireless internet
access zones.
[0142] In another application the transmitter 12 and transmitter
antenna 16 are integrated into a device that may be used to create
a HotSpot as described in the previous paragraph, the HotSpot may
be mobile for particular applications such as, but not limited to,
military missions in which a group of soldiers carry a portable
power generating source or a portable power storage source with the
transmitter 12 and transmitter antenna 16 integrated into or
otherwise connected to the source.
[0143] In another application the transmitter 12 and transmitter
antenna 16 are integrated into a device that may be used to create
a HotSpot, which may also be mobile. The device also has the
receiver 14 and plates 58 incorporated into it, effectively making
the device a power transceiver for both sending and receiving
wireless power.
[0144] In another application, any of the previously described
receiver devices may be a wireless power transceiver. That is, it
may be capable of both receiving and transmitting wireless
power.
[0145] Although embodiments have been described above with
reference to the figures, those of skill in the art will appreciate
that variations and modifications may be made without departing
from the scope thereof as defined by the appended claims.
* * * * *