Impedance transformation network for improved driver circuit performance
First Claim
1. A transmitter apparatus, comprising:
- a driver circuit characterized by an efficiency and a power output level, the driver circuit electrically connected to a transmit circuit having an impedance, the impedance of the transmit circuit within a complex impedance range including resistive and reactive variations, the complex impedance range defined by a minimum real impedance value, a maximum real impedance, a minimum imaginary impedance value, and a maximum imaginary impedance value, a ratio between the minimum and maximum real impedance value being at least two to one, a magnitude of the difference between the maximum and minimum imaginary impedance values being at least twice a magnitude of the difference between the minimum and maximum real impedance values; and
a filter circuit electrically connected to the driver circuit and configured to modify the impedance of the transmit circuit to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit when the impedance is within the complex impedance range,the filter circuit further configured to maintain a substantially constant power output level irrespective of the reactive variations within the complex impedance range, andthe filter circuit further configured to maintain a substantially linear relationship between the power output level and the resistive variations within the complex impedance range.
1 Assignment
0 Petitions
Accused Products
Abstract
This disclosure provides systems, methods and apparatus for reducing harmonic emissions. One aspect of the disclosure provides a transmitter apparatus. The transmitter apparatus includes a driver circuit characterized by an efficiency and a power output level. The driver circuit further includes a filter circuit electrically connected to the driver circuit and configured to modify the impedance of the transmit circuit to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit when the impedance is within the complex impedance range. The filter circuit is further configured to maintain a substantially constant power output level irrespective of the reactive variations within the complex impedance range. The filter circuit is further configured to maintain a substantially linear relationship between the power output level and the resistive variations within the impedance range.
-
Citations
31 Claims
-
1. A transmitter apparatus, comprising:
-
a driver circuit characterized by an efficiency and a power output level, the driver circuit electrically connected to a transmit circuit having an impedance, the impedance of the transmit circuit within a complex impedance range including resistive and reactive variations, the complex impedance range defined by a minimum real impedance value, a maximum real impedance, a minimum imaginary impedance value, and a maximum imaginary impedance value, a ratio between the minimum and maximum real impedance value being at least two to one, a magnitude of the difference between the maximum and minimum imaginary impedance values being at least twice a magnitude of the difference between the minimum and maximum real impedance values; and a filter circuit electrically connected to the driver circuit and configured to modify the impedance of the transmit circuit to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit when the impedance is within the complex impedance range, the filter circuit further configured to maintain a substantially constant power output level irrespective of the reactive variations within the complex impedance range, and the filter circuit further configured to maintain a substantially linear relationship between the power output level and the resistive variations within the complex impedance range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A method of selecting component values of one or more reactive components of a filter circuit for a wireless power transmitter device, the filter circuit electrically connected between a driver circuit and a transmit circuit, the method comprising:
-
determining a first set of complex impedance values for which efficiency of the driver circuit is above a threshold, the first set of complex impedance values substantially mapping to complex impedance values along a half circle path; determining a second set of complex impedance values for which power output of the driver circuit is substantially constant, the second set of complex impedance values substantially mapping to values along a full circle path that is orthogonal to the half circle and which crosses the half circle at a maximum; and selecting the component values to provide an impedance transformation that modifies a variable complex impedance of the transmit circuit to complex impedance values derived from the first and second sent of complex impedance values. - View Dependent Claims (16, 17, 18, 19)
-
-
20. A method of adjusting an impedance of a driver circuit characterized by an efficiency and a power output level, the driver circuit electrically connected to a transmit circuit having an impedance, the impedance of the transmit circuit within a complex impedance range including resistive and reactive variations, the complex impedance range defined by a minimum real impedance value, a maximum real impedance, a minimum imaginary impedance value, and a maximum imaginary impedance value, a ratio between the minimum and maximum real impedance value being at least two to one, a magnitude of the difference between the maximum and minimum imaginary impedance values being at least twice a magnitude of the difference between the minimum and maximum real impedance values, the method comprising:
-
modifying the impedance of the transmit circuit to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit when the impedance is within the complex impedance range; maintaining a substantially constant power output level irrespective of the reactive variations within the complex impedance range; and maintaining a substantially linear relationship between the power output level and the resistive variations within the complex impedance range. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
-
Specification