Linear circuit design-a multistage low noise amplifier

Accurate characterisation and modelling of the active devices is a prerequisite for successful amplifier design. Scalable S-parameter and noise models for FET's are investigated. Based on the results of the standard single gate FET, a modelling approach for devices in cascode configuration is presented which was validated up to W-band. An equivalent circuit based temperature noise model is proposed which can be successfully used for the design and simulation of MM-wave low noise amplifiers. To illustrate millimetre wave amplifier design techniques, a 2-stage cascode W-band amplifier with 20 dB gain at 110 GHz fabricated at FhG-IAF is discussed.