Impedance transformation network for improved driver circuit performance

摘要

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.

主权项

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.