A Recycling Krylov Subspace Method With High-Order Time Integration Methods for Fast Periodic AC and Noise Analysis

Periodic small-signal analysis plays an essential role in RF circuit simulation. These analyses encounter substantial computational complexity and memory requirements as the circuit size increases. To address this challenge, iterative solvers combined with the recycling Krylov subspace method between different frequencies have been proposed as a practical approach to speed up small-signal RF analysis. However, existing recycling iterative methods were derived only with the first-order backward Euler (BE) method. In this work, we propose a recycling Krylov subspace iteration method combined with high-order time integration methods to improve the efficiency of small-signal RF analysis. High-order time integration methods help reduce the time points involved in the preceding large-signal analysis and the matrix size of the small-signal equations in periodic small-signal analysis. The recycling Krylov subspace technology further accelerates the solution of these small-signal equations. Numerical experiments confirm the efficacy and advantages of the proposed method for Periodic AC (PAC) and Periodic Noise (PNoise) analysis.