Solving Structured Electronic Design of Negative Feedback Amplifiers as Nonlinear Programming Problems

This paper searches the best solution for the stages of noise and bandwidth of negative feedback amplifiers by resorting to Structured Electronic Design, through optimization methods. On one side, noise optimization is achieved by establishing the noise-characteristic as a function of bias current. On the other side, bandwidth optimization is obtained by establishing the equation for the open loop gain pole-product (LP product). Both aspects are defined as nonlinear programming (NLP) problems, where the design variables are related with the parameters of the device (bipolar transistors) used to synthesize the amplifiers. Differential Evolution is used to solve the noise NLP problem and the Hooke-Jeeves method is used to solve the bandwidth NLP problem. The obtained results are presented and some conclusions are established.