Current Mirror Bias Feedback for RF Amplifier Linearity

The patent implements feedback circuits that sample the amplifier output signal and feed it back to the bias circuits. This feedback mechanism allows the bias circuits to dynamically adjust and cancel non-linear distortion components, thereby improving signal linearity. The feedback path includes components such as resistors and capacitors that enable the circulation of distortion cancellation signals back to the amplifier input or bias nodes.

The patent divides the bias circuit into multiple independent bias circuits, each associated with specific amplifier devices. This segmentation allows individual optimization of each bias circuit to compensate for device-specific non-linearities. Each bias circuit can be independently controlled through its own feedback path, enabling precise distortion cancellation without affecting other parts of the amplifier.

The bias circuits in the patent serve multiple functions: they provide DC biasing for the amplifier devices and simultaneously act as distortion cancellation circuits through the feedback mechanism. This multi-functionality eliminates the need for separate distortion cancellation circuits, thereby reducing overall device complexity while maintaining effective linearity improvement.

The patent merges the feedback distortion cancellation path with the existing bias circuit architecture. Instead of adding completely separate feedback circuits, the design integrates distortion cancellation functionality into the bias circuit structure itself, sharing common components such as bias transistors and resistors between biasing and distortion cancellation functions.