Load mismatch adaptation in coupler-based amplifiers
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsLars Sundstrom, Per-Olof Brandt
Life of this patent
Estimating the term…
Abstract
Coupler-based amplifiers provide a measure of load mismatch based on the difference between the two output signal amplitudes from the amplifiers. This measure can be used to control variable matching networks (VMNs) or amplifier supply voltages to maintain constant distortion levels and high power transfer/efficiency and even to control output power. Load mismatch is measured by comparing the amplifier device output amplitudes and adjusting the circuit based on the comparison to counteract undesired behavior, such as increasing distortion levels.
Claims20
A coupler-based amplifier, comprising:
- a first branch amplifier device that produces a first branch output signal;
- a second branch amplifier device that produces a second branch output signal;
- a coupler connected to the first and second branch amplifier devices such that the first and second branch signals are combined for delivery to a load;
- a first envelope detector that produces a first envelope signal based on the first branch output signal;
- a second envelope detector that produces a second envelope signal based on the second branch output signal;
- and
- a differential device that forms a control signal corresponding to a difference between the first envelope signal and the second envelope signal, wherein the control signal is related to a reflection coefficient of the load.
A method of controlling a coupler-based amplifier that has at least two branch amplifier devices and a coupler that deliver a signal to a load, comprising the steps of:
- generating a control signal based on a difference between respective output signals generated by two branch amplifier devices, wherein the control signal is related to a reflection coefficient of the load;
- and
- controlling the two branch amplifier devices based on the control signal.
A coupler-based amplifier, comprising:
- a first branch amplifier device that produces a first branch output signal;
- a second branch amplifier device that produces a second branch output signal;
- a coupler connected to the first and second branch amplifier devices such that the first and second branch signals are combined for delivery to a load;
- a first envelope detector that produces a first envelope signal based on the first branch output signal;
- a second envelope detector that produces a second envelope signal based on the second branch output signal;
- a first adjustable power supply for the first branch amplifier;
- a second adjustable power supply for the second branch amplifier;
- a first differential device that forms a first control signal corresponding to a difference between the first envelope signal and an output level of the first adjustable power supply, wherein the first control signal is related to a reflection coefficient of the load;
- and
- a second differential device that forms a second control signal corresponding to a difference between the second envelope signal and an output level of the second adjustable power supply, wherein the second control signal is related to a reflection coefficient of the load;
- wherein the first control signal controls the output level of the first adjustable power supply and the second control signal controls the output level of the second adjustable power supply.
Dependencies are inferred from the claim text.