Optimization of RF low noise amplifier design using analytical model and genetic computation

Summarization: This paper introduces a methodology for optimum low noise amplifier (LNA) design, using a combination of analytical model and genetic algorithms. The optimum operation is defined by a figure of merit (FoM) that considers both the power efficiency and the RF performance of the device. This FoM suggests that the optimum region of operation lies in the moderate inversion. This knowledge can be used as a strong starting point for the design and optimization procedures. Initially, the LNA component values are determined using the analytical model. The analytical procedure does not account for all parasitics of the active and in particular the passive components, leading to a sub-optimal design. Therefore, the final LNA design is generated using full circuit simulation, where a genetic algorithm takes the analytical design as a starting point, aiming at faster convergence. To demonstrate the effectiveness of the methodology a 5 GHz common source LNA with inductive degeneration has been designed using a mixed signal/RF 90nm CMOS process.Presented on