Large-scale Electromagnetic Simulations Research Articles

Space-Time Adaptive Processing Concept for Calculation Speed Improvement in Multi-Region/FDTD Method

There has been an increase in demand for large-scale electromagnetic simulations, and the finite-difference time-domain (FDTD) method is one of the effective approaches. The multi-region (MR)/FDTD method allows the calculation of free space between the antenna and the objects to be omitted from the simulation model. This method utilizes the equivalence theorem to connect multiple regions, although in large-scale simulations, this approach is limited by its high time complexity. Thus, this communication proposes a space-time adaptive processing concept using a quadtree structure for adaptive processing to optimize the computation time of the MR/FDTD method. The effectiveness of the proposed method was confirmed using numerical simulations.

Performance analysis of parallelized PSTD-FDTD method for large-scale electromagnetic simulation

We developed a parallel solver for large-scale electromagnetic simulation by hybridizing the Pseudo-Spectral Time Domain (PSTD) and Finite Difference Time Domain (FDTD) methods. Parallelization is implemented with a Message Passing Interface (MPI) and Open Multi-Processing (OpenMP) and applied to a single spatial dimension in the full three-dimensional simulation. The stability and accuracy of the hybridized PSTD-FDTD (HPF) method are analyzed and compared with the FDTD method, in particular by applying to a known exact solution of the Mie scattering theory. We also present a roofline model analysis to explain the high computing speed of the HPF method despite its heavy computational loads. The HPF method features high stability, low parallelization cost and fast computing speed on the PC cluster, especially when the sampling rate is low.

Full-Wave Scattering and Imaging Characterization of Realistic Trees for FOPEN Sensing

The electromagnetic characterization of realistic tree structures is performed to facilitate the development of low-frequency (P-band) foliage penetration radars. The full-wave approach employs a parallelized 3-D finite-difference time-domain algorithm deployed on high-performance computing systems to simulate the far-field scattering responses from scenes. The backscattering behaviors of a single tree are first considered as a function of frequency, polarization, signal incidence angle, and structural fidelity, and then, large-scale simulations are carried out to examine the responses of a forest stand in both the frequency and imaging domains. The results featured are from the first phase of an ongoing study to investigate the feasibility of applying large-scale electromagnetic simulations to support airborne-based sensing of obscured ground targets.