K. Rada et al., PERFECTLY MATCHED LAYER FORMULATION FOR SIMULATING MICROWAVE AXISYMMETRICAL STRUCTURES USING FINITE-ELEMENTS, Electronics Letters, 32(16), 1996, pp. 1456-1457
The perfectly matched layer (PML) can be adapted in an unsplit form to
solve open microwave structures in the frequency domain. IThe authors
derive a finite element formulation for such layers, used to bound ax
isymmetric structures where their interface admits curvature.