loading page

Bipolar Junction Transistor Amplifiers-State-Space-Modeling Across Frequencies                           
  • +1
  • José M. Campos-Salazar,
  • Juan Aguayo,
  • Roya Rafiezadeh,
  • Gabriel Garcia-Rojas
José M. Campos-Salazar

Corresponding Author:[email protected]

Author Profile
Juan Aguayo
Author Profile
Roya Rafiezadeh
Author Profile
Gabriel Garcia-Rojas
Author Profile


This study presents a comprehensive analysis of three bipolar-junction-transistor (BJT) amplifier topologies common-emitter, common-collector, and common-base amplifiers-under transient conditions across low and high frequencies. Utilizing MATLAB-Simulink simulations, the response of each amplifier topology to varying frequency inputs is investigated, with a particular emphasis on state space modeling. Beginning with low-frequency models characterized by specific voltage or current sources, the study delves into the steady-state dynamics of output variables, employing state space equations to elucidate amplifier behavior. Notably, the common-emitter amplifier topology exhibits high gains, as corroborated by established literature, underlining its potential for high-performance applications. Conversely, the common-collector and common-base amplifier topologies demonstrate lower gains, reflecting distinct design characteristics. Transitioning to high-frequency operation, the impact of Miller capacitance on gain reduction is explored, especially pronounced in the common-emitter amplifier topology. Despite this, all amplifier configurations remain functional, with state space models validated through meticulous simulations. Simulation parameters are meticulously adjusted to accurately represent real-world scenarios, enhancing the reliability of the findings. These insights underscore the importance of comprehending amplifier behavior across different frequency domains, with state space modeling offering a powerful framework for analysis. By providing detailed insights into BJT amplifier performance under transient conditions, this study facilitates informed decisions regarding amplifier configuration selection and design, tailored to specific application requirements and frequency considerations.
17 May 2024Submitted to TechRxiv
23 May 2024Published in TechRxiv