Method of Moments Add-on

GRASP implements a highly advanced Accelerated Higher Order Method of Moments (MLFMM HO MoM) algorithm to solve huge scattering problems in short time and with substantially less memory requirements than any other known method. This is the result of several years of research carried out at TICRA, with special focus on providing our users with a tool that complements the standard PO implementation in GRASP, even for reflecting structures that are extremely large in terms of the wavelength.

Why use a full-wave solver?

PO is the tool of choice for reflector antenna analysis; it is fast and accurate for the most common applications. But a MoM solution may an interesting and viable alternative for:

  • Multiple interaction, e.g. beam-wave guide system. PO may be possible but requires substantial engineering insight to include all needed contributions
  • Scattering geometries with sharp corners of extreme curvatures, where PO predicts less accurate results, e.g. antenna support structures
  • Small antennas mounted directly on a platform
  • Wire antennas
  • Combination of all above, for example scattering in a satellite platform or in a baffle 


MoM currents calculated for the ESA PLANCK mission telescope. All interactions between the dual-reflector and huge baffle enclosing it are accounted for.

Efficient combination of MLFMM with higher-order basis functions.

GRASP users are typically facing very large scattering problems that are commonly involving curved structures. If a full-wave solution is required it is necessary with a tool that reduces memory as well as CPU time consumption. Higher-order methods are the natural choice, and GRASP performs an automatic meshing using curved patches, on which the currents are expanded in near-orthogonal higher-order basis functions. An efficient combination of MLFMM with HO MoM accomplishes the goals with respect to CPU time and memory simultaneously. The scattering from an entire satellite platform may be subject to detailed analysis with the MoM add-on.

Take advantage of the unique mesh-robust implementation and stop worrying about mesh connectivity.

Implementation of a discontinuous Galerkin method enables you to combine objects that are meshed with completely different parameters - an optimum approach in terms of efficiency. Moreover, it is easy to combine different input meshes, as the connectivity is controlled through a user-definable tolerance parameter.


Multi-mode waveguide ports enables the user to compute S-parameters of multiple horn antennas