Co-Simulation Design of BJT-Based LNA for Radio Frequency Front-Ends

A low noise amplifier (LNA), an essential element in radio frequency ($\mathbf{R F}$) front-ends, is principally tasked with amplifying feeble received signals to enhance overall system sensitivity. This study proposes a thorough co-simulation design of an LNA operating at S-band frequencies by utilizing a highperformance bipolar junction transistor (BJT) of BFP840ESD type. The co-simulation methodology combines circuit-level and electromagnetic (EM) evaluations to precisely determine the performance of LNA when being realized on a substrate. The design is deployed on an FR4 epoxy substrate with the dielectric constant of 4.3. The co-simulation result demonstrates a substantial gain achievement of 21.276 dB. This result enhances a prior schematic-level design by including the parasitic effects of passive components and interconnecting transmission lines, thus offering a more accurate evaluation on the performance. The attained enhancement underscores the efficacy of cosimulation methodology in optimizing LNA designs for S-band applications, providing a significant advancement over solely schematic-based design, enhancement gain, and facilitating improved RF performance.