# A PC-based High Frequency Electromagnetic Structure Simulator

#### Inexpensive software that allows design variations to be simulated and optimized quickly and easily

**A PC-based High Frequency Electromagnetic Structure Simulator **

**Infolytica Corp. Montreal, Quebec, Canada **

Three-dimensional (3-D) electromagnetic simulations of high frequency structures have been both time consuming and costly, running lengthy calculations on sophisticated workstations using expensive software. A new, inexpensive software package now allows the operator to simulate and optimize design variations quickly within 32-bit Windows® '95 and NT PC environments.

The FullWave 3-D high frequency electromagnetic structure simulator uses state-of-the-art technologies to generate a finite-element mesh transparently and employs an advanced solution technology for quickly generating accurate full-wave solutions of arbitrary-shaped 3-D high frequency structures. The software package includes capabilities for parametrization, animation of 3-D electromagnetic fields and determining resonant modes and scattering parameters. It was designed on PCs to take advantage of the Windows '95/NT features, such as pull-down menus, button bars, tab bars, graphic interactivity with the model and on-line help.

**A 3-D adaptive Field Solver**

FullWave incorporates an adaptive field solver of the time harmonic Maxwell's equations that analyzes arbitrary 3-D high frequency structures using exclusive iterative and direct solvers. FullWave models 3-D high frequency structures quickly with access ports through which energy enters and leaves, as shown in **Figures 1** and **2** . Arbitrary-shaped waveguides or transmission lines can be connected to these ports. A component may have different waveguides or transmission lines at different ports, thereby permitting the analysis of transitions from one waveguide to another or from transmission line to waveguide. The simulator computes the scattering matrix of the structure as well as port modal solutions. The results then can be exported to microwave circuit analysis packages in Touchstone,® Citifile® and Supercompact® formats.

When computing a solution, the software first performs a two-dimensional (2-D) modal analysis at the ports that can be performed independently of the 3-D simulation. The simulator handles structures composed of a combination of dielectric and magnetic materials. A choice of definitions for characteristic impedance is available. De-embedding allows for arbitrary port lengths. Electric and magnetic wall boundary conditions are modeled. The electric wall allows the user to define the conductor, and the magnetic wall (perfect magnetic conductor) is used to take advantage of symmetry planes to reduce model size. An internal library lists the properties of commonly used dielectric, conducting and magnetic materials for reference, and new materials can be added.

**Simulator Outputs**

The FullWave simulator computes the generalized scattering matrix (including higher order modes) of the structure, as well as the impedance and admittance matrices. The renormalized scattering matrix then can be exported to microwave circuit analysis packages. The electric field is computed directly, and the user can view either the E- or H-field for each frequency. The field that is present in the component when a selected port is excited is displayed, while other ports are matched. The field can be viewed in 3-D as a static or animated display. When computing a solution, the package performs a 2-D modal analysis. The user also can elect to perform this analysis independently of the 3-D solution.

**Applications**

FullWave software is suitable for the design of components that are constructed using microstrip or planar transmission lines and PCB techniques, as well as IC and MMIC devices for use in RF and microwave applications. Typical structures analyzed include transitions; discontinuities; corners; bends and twists; posts, irises and other obstacles; and tapers, steps and T-junctions. The program is useful for performing electromagnetic characterizations of components such as connectors, filters, power dividers and combiners, directional couplers, attenuators, terminations, multiplexers and resonators.

**Conclusion**

The FullWave software package permits the user to simulate and optimize design variations quickly, eliminating lengthy and expensive laboratory testing. The software utilizes state-of-the-art technologies for generating a finite-element mesh transparently, parametrization of design variables and advanced solution technologies for generating accurate solutions rapidly on a PC.

The simulator's first version is suitable for microwave (bounded) problems. The product is available currently for limited release. FullWave's single-installation list price is $28,000. Multiple copy, network license, educational and site license discounts are available.

*Infolytica Corp., Montreal, Quebec, Canada (514) 849-8752.*