California’s Applied Wave Research has released a ‘planar 3D’ electromagnetic (EM) modelling package.

Planar 3D differentiates the modelling from true arbitrary 3D modelling, and in this case means that the structure to be modelled is split up into a stack of 2D layers.

From the top, the layers are segmented into arbitrary triangles and rectangles. In this way, the majority of elements resembles wedges of cheese standing up.

“The assumption is that the dielectric is 2D. You can have stacked layers of dielectric with current flow in 3D, so it is good for PCBs or chips,” Sherry Hess, v-p of marketing at AWR told EW. “It is more accurate that arbitrary 3D solvers in highly planar structured.”

Called Axiem, the product is related to the firm’s EMSight which is limited to a grid of rectangular elements.

Like EMSight, Axiem is a method-of-moments (MoM) solver. However, it is not a standard MoM solver.

Where N is the number of unknowns in a structure, “the proprietary technique is best-described as similar to the fast multipole method, yet adapted for full-wave analysis”, said AWR. “As such, the solver algorithm scales on the order of N log(N) as opposed to N[super3] - the case for most existing MoM products.”

This complexity reduction makes it over 10 million times faster with 10,000 unknowns. “We think between 100,000 and one million unknowns is where it will be used,” said Hess. “Computations today lie at less than 100,000 unknowns.”
Do you loose anything along with gaining this speed? “No,” said Hess who also claims the maths behind Axiem works where traditional method of moments has not done very well: with thick metal layers where conductor width and thickness are similar.

With the dramatic increase in speed available, the firm is marketing Axiem as a tool that can be used repeatedly on layout iterations, rather than saving it until electrical iterations are complete. “The algorithms allow designers of today’s electronic products to migrate EM analysis from pure back-end post verification to upfront diagnostic design,” said AWR. Applications are foreseen in the design of RF PCBs, modules, LTCCs (low temperature co-fired ceramics), MMICs (monolithic microwave ICs), and RFIC designs.