RF communications devices, such as circulators, isolators, signal filters and couplers; must keep up with advancements in technology, such as 5G MIMO, Internet of Things (IoT) and SatCom. Traditional modelling approaches to magnetic materials, such as linearized permeability tensors, fail to adequately capture the physics required to develop state-of-the-art components and devices. To overcome this limitation, MaxLLG, a University of Exeter spin-out company originating from the ICURe programme, has developed a solver which couples the nonlinear Landau-Lifshitz-Gilbert equation with the complete solution of Maxwell’s equations, making it possible to simulate electromagnetic propagation in any magnetic or nonmagnetic medium