Patent ID: 7679448

Claim:
A biasing circuit for varying distortion in a first transistor, the biasing circuit comprising: a replica of the first transistor; a first continuous wave (CW) source for providing a first CW signal at an input of the replica transistor to obtain an output signal at an output of the replica transistor, the first CW signal having a frequency f o , the output signal having an N th -order distortion component at a frequency N*f o , N being an integer greater than one; a second CW source for generating a second CW signal having a frequency N*f o ; a mixer for mixing the output signal with the second CW signal to obtain a mixed signal having a DC component with an intensity proportional to a value of the N th -order distortion component; and a bias controller for receiving the mixed signal and for biasing the input of the first transistor in accordance with the value of the N th -order distortion component.