Frequently Asked Questions

General

Advantages of WIPL-D software

Which professional problems can I solve using WIPL-D software?

Modeling

Prices, special offers, discounts...

Support, training, news group info, consulting

General

What is WIPL-D Pro?

WIPL-D Pro is a general 3D electromagnetic solver that analyzes arbitrary metallic and/or dielectric structure in the frequency domain.

What is the difference between WIPL and WIPL-D software?

WIPL software packages are DOS programs for electromagnetic modeling of composite wire and plate structures. Lite version was distributed by Artech House from 1995, and Professional version was distributed by authors. WIPL-D software packages are Windows programs, which evolved from WIPL software packages.  The new programs were upgraded to include lossy/lossless dielectric/magnetic objects into the analysis and many new features were added since then. Lite version was distributed by Artech House from 2000, and Pro version was distributed by WIPL-D d.o.o.

What does the abbreviation WIPL-D stands for?

WI stands for wires, PL stands for plates, and D stands for dielectrics.

What is the difference between Lite and Pro version?

Generally speaking, the Pro version can handle 10-100 times more complex structures than the Lite version. In order to facilitate creation, analysis and presentation of results, many new options are added in the Pro version.

What is the theoretical basis of WIPL-D Pro kernel?

MoM (Method of Moments) / (surface integral equations) / surfaces equivalence theorem / wires - right truncated cones (cylinders) / plates - bilinear surfaces (flat quads) / wire-to-plate junctions / automatic meshing of electrically large plates /  polynomial approximation of currents (higher order, rooftop) / automatic satisfaction of current continuity at free ends and multiple junctions / LU decomposition / CG iterative method. (The kernel of WIPL-D Pro is an original product and is theoretically well documented with more than 30 referenced IEE and IEEE journal and conference articles.)

What are the hardware and software requirements for WIPL-D Pro?

WIPL-D Pro runs on a minimum configuration consisting of an Pentium, and other 100% compatible computers, running Win 98 or later versions of Windows ( including Windows NT ). Minimum of 128 MB hard disk space is required. Size of RAM depends on number of unknowns N required for an analysis: 8*N*N bytes (for single precision) and 16*N*N bytes (for double precision) (e.g. 128 MB and 256 MB for N=4000). Support for graphics, printers, and mouse is provided by Windows.

Who are intended users?

Intended users are engineers, scientists and graduate students, involved in the research and design of various types of antennas, scatterers, passive microwave circuit components and EMC facilities.

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Advantages of WIPL-D software

What is the advantage of WIPL-D software over codes using wire-grid modeling?

WIPL-D software models metallic and dielectric surfaces by quadrilateral patches. Wire-grid modeling requires much more elements and unknowns than surface patch modeling. The analysis of solid surface metallic models based on wire-grid modeling is about 10 times more time consuming than those based on surface patch modeling. Wire-grid modeling can not be applied to dielectric surfaces. WIPL-D software can be used for both types of modeling, but surface patch modeling is recommended.

What is advantage of the WIPL-D software over the FEM and MoM/VIE based programs?

WIPL-D software is based on the MoM/SIE. In the MoM/SIE the unknown quantities are surface currents, while in the FEM and MoM/VIE the unknown quantities are volume fields and currents. Hence, the number of unknowns and analysis time required by the MoM/SIE are usually much lower than those of the FEM and MoM/VIE. In particular, the FEM and MoM/VIE can not easily model wire and thin plate structures.

What is the advantage of WIPL-D software over time domain analysis?

WIPL-D software performs analysis in the frequency domain. Frequency domain analysis is always performed at one frequency at a time. In order to obtain the same result by time domain analysis, the analysis should be performed in a long enough time interval, and than Fourier transform must be applied. This is an indirect way of obtaining results in the frequency domain and because of that it is less efficient.

What is the advantage of the WIPL-D software over the FD-TD?

WIPL-D software is based on the MoM/SIE, and because of that it does not need any absorbing boundary conditions and discretization of the volume outside of the device under investigation. Accuracy of the FD-TD modeling is mostly related to the discretization quality and minimum one discretization point per tenth of the wavelength is recommended. This leads, in case of electrically large structures, to a very high number of discretization points and usually huge time of computation. If the actual result is wanted at one frequency or at selected number of frequencies, it may be expected that WIPL-D software may need an order of magnitude shorter computation time.

What is the advantage of the WIPL-D software over codes that treat substrates as infinite layers?

WIPL-D software treats all layers in an absolutely realistic way, as finite 3D dielectric bodies, which can have holes, dielectric addendums, etc.

What is the advantage of WIPL-D software over codes based on triangle patch modeling?

WIPL-D software is based on quadrilateral patch modeling. When rooftop basis functions are used, the quadrilateral modeling is two times more efficient than triangular modeling. In addition, WIPL-D Pro combines quadrilateral modeling with higher order basis functions, thus requiring an order of magnitude less number of unknowns than classical triangular modeling.

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Which professional problems can I solve using WIPL-D software?

What are the typical electrical quantities provided by WIPL-D software?

WIPL-D software provides current distribution over the structure's surface, network parameters of multiport devices (y, z, s-parameters), radiation pattern of antennas, antenna arrays and other radiating structures, and near field everywhere inside and outside the structure (e.g., inside EMC facilities, inside human tissues, and in the vicinity of antennas).

What are the typical antennas and antenna arrays that WIPL-D software can handle?

Yagi-Uda arrays / log-periodic antennas / wire and strip helicoidal antennas / metallic or dielectric horns excited by probe fed waveguides / reflector antennas with feeds and feed struts / slotted waveguide arrays / microstrip patch antennas over finite substrates / dielectric rod and resonator antennas / lens antennas.

May I model antennas mounted on vehicles (airplanes) and still use PC for modeling?

YES. WIPL-D software offers very effective calculation. The required number of the unknowns per square wavelength for electrically large plates is very small (10-20). This is the essential difference and advantage over other frequency domain codes. Using 15000 unknowns and 3 symmetry planes WIPL-D Pro can handle structures up to 10 000 wavelength squared.

Does WIPL-D software take into account influence of a radome on antenna characteristics?

YES. WIPL-D software offers very precise modeling of radomes as dielectric bodies, or very efficient modeling using distributed loading option.

May I model antennas above the real ground using WIPL-D Pro?

YES. The influence of ground on the current distribution is taken into account by a ground clamp below the antenna.

Can I use WIPL-D Pro to de-embed s-parameters of multiport devices, modeled together with real feeding structures?

YES. The de-embedding procedure for the s-parameter extraction is provided as a feature of the WIPL-D Pro. You can even apply the procedure to determine s-parameters of new types of discontinuities of new types of guiding structures.

Is WIPL-D software able to model and analyze planar (single and multi-layer) structures?

YES. However, WIPL-D software models planar structures as finite-size structures. (All layers are modeled as finite-sized bodies. Ground planes can be modeled as infinite PECs, or as finite-size metallic plates).

Can I calculate complex waveguide junctions and filters using WIPL-D software?

YES. WIPL-D software is already tested and applied for designs of the 3D dielectric filters for a large wireless company, with success. Waveguide structures, corrugated horn antennas with feedings, cavity filter designs are tested.

May I efficiently model 3D TEM cell and other EMC facilities by WIPL-D software?

YES. Owing to high efficiency, the analysis can be performed at very high frequencies (at which 3D cell becomes electrically very large). Due to smart interpolation, WIPL-D Pro obtains response in wide frequency range using reduced number of frequency samples.

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Modeling

May I specify lossy materials, with possibly high dielectric and magnetic constant?

YES. Stable results are obtained if product of relative electric and magnetic constant is less than 1000.

Can I take into account skin-effect losses?

YES. Skin-effect is treated as specific distributed loading. You can define different specific conductivities for various wires, plates, or their groups.

May I take into account end effect or abrupt changes in wire radius of fat wires?

You can adjust independently starting and ending wire radius. Wire end can be represented as almost flat cone, while abrupt change of wire radius can be represented as almost flat frill.

How can I model curved surfaces with quadrilateral surface patches?

WIPL-D quads are the simplest surfaces defined by four arbitrary-spaced nodes. In particular, WIPL-D software has routines for creation of some basic curved surfaces (spheres, ellipsoids, super spheroids, parabolic surfaces, etc.).

Is there any limitation regarding wire-to-plate junctions?

NO. You can attach a wire in the middle of a plate, to plate edge, to plate corner, to wedge and to tip of a metallic body. It is only recommended not to connect more than two wires to a plate.

How may I input my object topology efficiently?

WIPL-D Pro offers a lot of functions for generating complex three-dimensional models (Generalised sphere, circle, reflector, BoR, BoT, BoCC, BoCG, Helix, etc.) and combining them using manipulations (move, rotate, scale, copy, group, etc.). You can create your own library with predefined sub-structures, which can be imported into the current project. Using grids to define plates and nodes may be applied as well as generating the structure by AutoCAD tool.

May I transfer an AUTO CAD model of the scattering object into WIPL-D Pro input data file?

YES. We have a special product, AW Converter, which enables such transfer.

How should I perform structure optimization?

WIPL-D Pro offers very easy symbolic definition of the geometrical sizes, including symbol definition by the mathematical combination of the different symbols, previously defined. This allows simple control of the key parameters to be optimized. WIPL-D Optimizer enables you to optimize your structure to satisfy some given criteria. All efficient optimization routines are available, including Genetic algorithm, Simulated Annealing, Simplex,  Gradient, Random and Systematic Search.

What solvers do you use in your kernel?

Direct solvers (LU decomposition) and iterative solvers (CG method) are included in WIPL-D Pro software kernel.

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Prices, special offers, discounts...

What is the price of the professional versions of your products?

For a detailed pricing list and all the purchasing options please contact our sales.

Do you have special purchase conditions for universities?

Basically, for education we recommend universities to purchase from Artech House the low cost Lite version (less than 400 USD), which can be used at 5 working places in a classroom or in a lab.

In the case of a commercial project related co-operation of the University chair with Industry, we offer the  professional version for 70% of the official price. Other discounts and special offers may also be available. Contact our sales to get the offer that best meets your demands.

May I obtain the test evaluation version of the program?

As a first step we recommend you to download free demo of the WIPL-D (Lite), which is limited to 48 unknowns. That way you gain insight into capabilities of WIPL-D software. For thorough testing of WIPL-D Pro please contact our Sales Department.  

Do you provide floating licence option?

NO, at the moment. Only node locked (dongle based) PC version is currently available. However this may be offered in the near future.

How many installations do you have worldwide?

We have around 800 licences of lite version and more than 150 licences of professional version worldwide.

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Support, training, news group info, consulting

Where and how do you provide training courses?

We provide training courses at time to time, and per request of users.

What kind of support do you offer?

Basically, we give support by e-mail, usually within 24 hours. We also provide telephone support during our working hours: 7-15 GMT on workdays.

Do you provide service for modeling the structures so that we from our side may make only the optimizations of the model?

A full WIPL-D modeling capability is offered on the competitive engineering rate. Please, contact us, for more details.

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