Automated synthesis of microwave low-noise amplifiers using genetic algorithm and ideal impedance transformers

Abstract: In this article, a new technique for the automated genetic-algorithm-based synthesis of linear and low-noise microwave transistor amplifiers is presented. It uses idealized models of lossless correcting-matching networks, i.e., ideal impedance transformers that can be tuned for the maximum gain or minimum noise of active elements. Also, a modified version of the technique is described that allows the synthesis of separate amplifier stages. Both technique versions reduce the dimension of the search space for genetic algorithm shorting the synthesis time and improving performances of multistage microwave amplifiers. The approach is implemented in the new version of software tool Geneamp. The efficiency of new technique is demonstrated in the example design of 1– 2 GHz three-stage LNA.

Keywords: microwave transistor amplifier, lna, synthesis, genetic algorithm, ideal impedance transformer