Nonlinear properties of gallium arsenide and silicon FET-based RF and microwave switches

An important parameter for RF and microwave system design is the prediction of distortion produced by system components. This paper presents the results of a study on modeling the distortion produced by silicon and gallium arsenide RF and microwave switches. Exact relationships for the second and third order intercept point as a function of FET parameters are presented. The results indicate that both types of FET-based switches have higher levels of distortion at low frequencies. The distortion improves at frequencies above the gate bias circuit cutoff frequency, although the distortion improvement is lower for the MOSFET-based switch.