booktext@id88013716placeboieFundamentals of RF Circuit Design with Low Noise Oscillators. Jeremy Everard Copyright 2001 John Wiley & Sons Ltd ISBNs: 0-471-49793-2 (Hardback); 0-470-84175-3 (Electronic) 2 Two Port Network Parameters 2.1 Introduction This chapter will describe the important linear parameters which are currently used to characterise two port networks. These parameters enable manipulation and optimisation of RF circuits and lead to a number of figures of merit for devices and circuits. Commonly used figures of merit include hFE, the short circuit low frequency current gain, fT, the transition frequency at which the modulus of the short circuit current gain equals one, GUM (Maximum Unilateral Gain), the gain when the device is matched at the input and the output and the internal feedback has been assum……