GPU accelerated FDTD solver algorithm for radiation from MMIC passive components

GPU (Graphical Processing Unit) acceleration algorithm for an FDTD (Finite-Difference Time-Domain) solver analyzing radiation from MMIC (Monolithic Microwave Integrated Circuit) passive components is presented. Total power and radiation patterns of fields not only radiated into the half-space region but also scattered along the substrate as surface waves can be very accurately evaluated. Tangential fields on a cuboid surface enclosing objects of calculation are used as source fields for evaluating radiated fields. These source fields are obtained through use of conventional FDTD calculation of fields produced by time-harmonic wave excitation and time integration over the last one period. This source field calculation as well as usual FDTD field calculation in the whole region is done in the GPU device. Thus, about 10 times speedup ratio compared with GPU-less calculation is attained under the circumstances of two Intel Xeon(R) E5620 CPUs (total 8 cores) and one Tesla C2075 GPU. Calculation algorithm using GPU device is explained in detail. Theoretical procedures developed by the author for obtaining radiated fields from source fields are also reviewed briefly. Numerical examples are given for a step index low pass filter.