Abstract :
I found the short paper of K. B. Niclas "The Exact Noise Figure of Amplifiers with Parallel Feedback and Lossy Matching Circuits" very interesting, but, except for the approximated formulas, it contained only little new information, since my paper "Simultaneous Input Power Match and Noise Optimization using Feedback" [2] included most of the formulas. In that paper, I have developed a general form of noise parameters of a three-port with combinations of parallel and series feedback (or imbedding) elements. These formulas include both the formula of Niclas and of Iversen [1, [9]]. The formulas have been used in the lossless case to develop an amplifier with simultaneous noise and power input match.
