Wireless power receiver system circuit
Wireless power transfer systems, disclosed, include one or more circuits to facilitate high power transfer at high frequencies. Such wireless power transfer systems may include a damping circuit, configured to dampen a wireless power signal such that communications fidelity is upheld at high power. Additionally or alternatively, such wireless power transfer systems may include voltage isolation circuits, to isolate components of the wireless receiver systems from high voltage signals intended for a load associated with the receiver. Utilizing such systems enables wireless power transfer at high frequency, such as 13.56 MHz, at voltages over 1 Watt, while maintaining fidelity of in-band communications associated with the higher power wireless power signal.
1 . A wireless power receiver system circuit comprising:
a receiver antenna operable to (i) couple with a transmitter antenna via an alternating electromagnetic field, wherein the alternating electromagnetic field is operable to deliver power and in-band data to the wireless power receiver system circuit and (ii) produce an alternating current (“AC”) power signal based on the alternating electromagnetic field;
a power conditioning system operable to (i) receive the AC power signal, (ii) convert the AC power signal to a DC power signal, and (iii) provide the DC power signal to, at least, a load associated with the wireless power receiver system circuit;
a receiver control system;
a controller capacitor electrically connected in series with a data input of the receiver control system; and
a voltage isolation circuit comprising:
a first isolation capacitor electrically connected to the receiver antenna and operable to receive the AC power signal; and
a second isolation capacitor electrically connected in series with respect to the first isolation capacitor and operable to provide the AC power signal to the power conditioning system, wherein the voltage isolation circuit is electrically connected to the controller capacitor at a node between the first isolation capacitor and the second isolation capacitor, and
wherein the controller capacitor is operable to:
receive the AC power signal from the voltage isolation circuit, the AC power signal having a range of voltages and including the in-band data;
regulate the AC power signal to generate a scaled AC power signal having a reduced range of voltages while maintaining the in-band data;
provide the in-band data, in-band of the scaled AC power signal, to the data input of the receiver control system via the controller capacitor; and
isolate the reduced range of voltages of the scaled AC power signal at the receiver control system from a load voltage at the load associated with the wireless power receiver system circuit.
2 . The wireless power receiver system circuit of claim 1 :
wherein the voltage isolation circuit has a total capacitance (C TOTAL ) that is a constant configured for a threshold range of voltages acceptable by the receiver control system;
wherein the first isolation capacitor has a first capacitance value (C ISO1 );
wherein the second isolation capacitor has a second capacitance value (C ISO2 ); and
wherein C ISO1 and C ISO2 are set such that:
C
ISO
1
=
C
TOTAL
*
(
1
+
t
ν
)
t
V
,
C
ISO
2
=
C
TOTAL
*
(
1
+
t
v
)
.
3 . The wireless power receiver system circuit of claim 2 , wherein tv is a scaling factor with a value in a range of about 3 to about 10.
4 . The wireless power receiver system circuit of claim 1 , wherein the voltage isolation circuit is further electrically connected to a shunt capacitor at the node between the first isolation capacitor and the receiver antenna.
5 . The wireless power receiver system circuit of claim 1 , wherein the AC power signal produced by the receiver antenna is greater than 1 Watt.
6 . The wireless power receiver system circuit of claim 1 , wherein the receiver control system is configured to decode the in-band data of the alternating electromagnetic field that was encoded via on-off-keying the alternating electromagnetic field.
7 . The wireless power receiver system circuit of claim 1 , wherein the wireless power receiver system circuit is configured to operate at an operating frequency within a range of about 13.553 megahertz (“MHz”) to about 13.567 MHz.
8 . A method for operating a wireless power receiver system circuit, the wireless power receiver system circuit comprising (i) a receiver antenna, (ii) a power conditioning system, (iii) a receiver control system, (iv) a controller capacitor electrically connected in series with a data input of the receiver control system, and a voltage isolation circuit comprising (a) a first isolation capacitor electrically connected to the receiver antenna and (b) a second isolation capacitor electrically connected in series with respect to the first isolation capacitor, wherein the voltage isolation circuit is electrically connected to a controller capacitor at a node between the first isolation capacitor and the second isolation capacitor, the method comprising:
coupling the receiver antenna with a transmitter antenna, via an alternating electromagnetic field that is (i) generated by the transmitter antenna and (ii) operable to deliver power and in-band data to the wireless power receiver system circuit;
producing, using the receiver antenna, an alternating current (“AC”) power signal based on the alternating electromagnetic field, the AC power signal configured to deliver the power and in-band data;
receiving, at the voltage isolation circuit, the AC power signal from the receiver antenna, the AC power signal having a range of voltages and in-band data;
receiving, at the power conditioning system via the second isolation capacitor, the AC power signal;
converting, via the power conditioning system, the AC power signal to a direct current (“DC”) power signal;
providing, via the power conditioning system, a DC power signal to, at least, a load associated with the wireless power receiver system circuit;
receiving, via the controller capacitor, the AC power signal;
regulating the AC power signal by the controller capacitor to generate a scaled AC power signal having a reduced range of voltages while maintaining the in-band data;
providing the in-band data, which is in-band of the scaled AC power signal, to a data input of a receiver controller via the controller capacitor, the controller capacitor further electrically connected in series with the data input of the receiver controller; and
isolating the reduced range of voltages of the scaled AC power signal at the receiver controller from a load voltage at the load associated with the wireless power receiver system circuit.
9 . The method of claim 8 :
wherein the voltage isolation circuit has a total capacitance (C TOTAL ) that is a constant configured for a threshold range of voltages acceptable by the receiver control system;
wherein the first isolation capacitor has a first capacitance value (C ISO1 );
wherein the second isolation capacitor has a second capacitance value (C ISO2 ); and
wherein the method further comprises setting C ISO1 and C ISO2 such that:
C
ISO
1
=
C
TOTAL
*
(
1
+
t
ν
)
t
V
,
C
ISO
2
=
C
TOTAL
*
(
1
+
t
v
)
.
10 . The method of claim 9 , further comprising:
setting tv to a value within a range of about 3 to about 10, tv comprising a scaling factor.
11 . The method of claim 8 , wherein the voltage isolation circuit is further electrically connected to a shunt capacitor at a node between the first isolation capacitor and the receiver antenna.
12 . The method of claim 8 , wherein the AC power signal produced by the receiver antenna is greater than 1 Watt.
13 . The method of claim 8 , further comprising decoding, using the receiver control system, the in-band data of the alternating electromagnetic field that was encoded via on-off-keying the alternating electromagnetic field.
14 . The method of claim 8 , wherein the wireless power receiver system circuit is configured to operate at an operating frequency within a range of about 13.553 megahertz (“MHz”) to about 13.567 MHz.