Patent ID: 8050644

Claim:
A method for cancelling channel resistance modulation in a field effect transistor (FET) used in a frequency mixer, the mixer combining a received radio frequency (RF) input signal with a local oscillator (LO) signal to provide an intermediate frequency (IF) signal, wherein a FET has a gate, a source, and a drain, wherein a voltage appears at each of the gate, the source, and the drain when the FET is conducting, and wherein the modulation of the channel resistance is caused by modulation of the voltage of the RF input signal, comprising: applying a bias to the FET to distinguish the drain from the source such that channel resistance is associated with voltage between the gate and the source; superimposing at least a portion of the voltage of the RF input signal (RF voltage) on the LO signal to form a modified LO signal; and inputting the modified LO signal to the gate while inputting the RF input signal to the source.