Tool comparisons, a matched-mesh FDTD benchmark, antenna how-tos, and how RayRF is checked against measured hardware. Written for working RF engineers.
A simulator is only as good as its agreement with hardware. RayRF was checked against 43 structures measured on a VNA, with many resonances matching within 1 percent. The method and the honest caveats.
CST Studio Suite is a broad, expensive 3D EM suite. For planar PCB RF, RayRF is a GPU FDTD tool at 1,499 USD per year with live results. What you keep and what you give up.
HFSS is powerful and expensive. For planar PCB RF, RayRF is a GPU FDTD tool at 1,499 USD per year with a GUI and fast iteration. An honest look at what you gain and what you give up.
A like-for-like FDTD benchmark: a 46.8M-cell 5.8 GHz patch, 5,000 timesteps, one workstation. RayRF GPU ran 68.5x faster than openEMS (9,843 vs 144 MCell/s, 25.4 s vs 27m44s). Numbers and method.
A practical walkthrough: estimate patch dimensions, build the stackup and feed, run a full-wave FDTD solve, read S11, and tune the match. Uses free calculators and RayRF.
openEMS is free and capable but needs scripting and runs on CPU. RayRF is a GUI FDTD simulator with a GPU solver that ran a head-to-head patch case 68.5x faster. An honest comparison.
FDTD, the finite-difference time-domain method, steps the electric and magnetic fields forward in time on a grid. A plain explanation of how it works, its trade-offs, and why GPUs suit it.