FDTD method for transmission lines with nonlinear diode using MATLAB

Abstract

This dissertation presents an efficient method for Finite-Difference Time-Domain (FDTD) simulation of transmission lines containing nonlinear diodes. This approach allows for a more accurate representation of diode behavior by introducing an intermediate variable at each time step and solving a quadratic equation for it. This method differs from traditional algorithms in that it directly updates the field without iterative computation. The advantage of this approach is that it avoids the complexity and computational cost associated with iterative calculations, such as Newton-Raphson methods. The method eliminates the need for specialized update equations and reduces the computational burden, making it a practical and efficient solution for simulating nonlinear devices in FDTD. In order to assess whether the suggested strategy is effective, the simulation results obtained using Matlab are compared with the results from a commercial simulation circuit package, Advanced Design System (ADS). The comparison demonstrates good accuracy and stability, further supporting the suitability of this method for accurately simulating nonlinear devices. Overall, the proposed method provides a valuable contribution to the integration of nonlinear diodes into the FDTD method, offering improved accuracy, efficiency, and ease of implementation in FDTD simulations. It opens up possibilities for simulating and analyzing various nonlinear devices with reduced computational complexity, enabling more advanced and realistic electromagnetic simulations.