Receiver linearity measurement using two CW signals

Receiver linearity is a measure of the variation in the gain of the receiver as a function of incident power. In a completely linear ideal receiver, the gain would be the same regardless of power, but real detectors may exhibit gain variation for a variety of reasons. The ability to specify the linearity of a detector is determined by both the linearity of the detector and the accuracy of the linearity test. Traditional methods rely on the linearity and accuracy of a reference device such as power sensors and step attenuators. This paper presents a new method that does not depend on other reference standards, that is capable of detecting very small linearity errors of modern RF receivers, that is repeatable and reproducible, that can operate over a very wider frequency range and is traceable to fundamental units (UI).