APPARATUS AND METHODS FOR DC BIAS TO IMPROVE LINEARITY IN SIGNAL PROCESSING CIRCUITS

摘要

To maintain linear operation of a signal processing circuit, such as a low noise amplifier, a peak detector detects a peak of a signal associated with the signal processing circuit and compares the detected peak signal with a threshold. When the detected peak signal is greater than the threshold, a variable current source biases the signal processing circuit to place the signal processing circuit in a different mode of operation. The signal processing circuit may thereby process a larger input signal while operating in an acceptable linear region.

主权项

1. A circuit assembly comprising:
first and second signal processing circuits, each including a biasing circuit and a biasing current source configured to provide a biasing current to the biasing circuit, each of the first and second signal processing circuits configured to receive a radio frequency (RF) input signal and to generate an output signal, an RF output signal including the output signal of the first and second signal processing circuits; first and second current sources respectively configured to provide additional current to the biasing circuits of the first and second signal processing circuits, the first current source configured to be enabled when a first threshold is detected; and a first switch separate from the second current source and in communication with the second current source, the first switch configured to enable the second current source when a second threshold is detected.