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Antenna Modeling Software

Some Antenna Modeling Programs

L. B. Cebik, W4RNL

Some Antenna Modeling Programs L. Much of my antenna research work is based on systematic antenna modeling in a version of the Numerical Electro-magnetics Code (NEC). The following brief notes will provide links to known antenna modeling software providers. ASAP - Antenna Scatterers Analysis Program, is a Free general purpose antenna analysis software program for numerical electromagnetic antenna design, modeling and analysis. Source code and windows executables are available to download. AutoEZ - Automated use of EZNEC. EZNEC Antenna Software by W7EL. Above: Screen shots from several EZNEC v. Right: 3D far field pattern, with 2D elevation 'slice' highlighted. Any azimuth or elevation slice can be highlighted. Center: View Antenna display, showing the 'wires' making up the model of the five-element beam, with currents and 2D. NEC v5.0 is the latest version of LLNL’s decades-long successful NEC antenna modeling software family. NEC v5.0 models the electromagnetic response of antennas and scatters consisting of wires and conducting surfaces. Input commands can generate a number of wire and surface shapes that can be combined for complex models.

4nec2 is a completely free Nec2, Nec4 and windows based tool for creating, viewing, optimizing and checking 2D and 3D style antenna geometry structures and generate, display and/or compare near/far-field radiation patterns for both the starting and experienced antenna modeler.


Much of my antenna research work is based on systematic antenna modeling in a version of the Numerical Electro-magnetics Code (NEC). The following brief notes will provide links to known antenna modeling software providers.

NEC-4

Antenna Modeling Software The latest version of NEC is NEC-4, which overcomes most of the shortcomings with earlier codes. It permits the modeling of underground radial systems, elements of varying diameter sections, carefully-constructed close-spaced parallel wires, as well as all the modeling capabilities of earlier versions of the code. NEC-4 is a proprietary code of the University of California, from whom a user-license must be obtained. Export restrictions apply. Antenna modeling software mac

At present, I know of only two sources of commercial software for NEC-4:

Eznec Antenna Modeling Software

Roy Lewallen, W7EL produces EZNEC Pro, which has an option for NEC-4, if the purchaser has a confirmed license for NEC-4. EZNEC Pro is also available for NEC-2 (see below). W7EL also makes available EZNEC, a segment-restricted version of NEC-2, and ELNEC, a version of MININEC 3. All W7EL software packages are currently for DOS and employ similar user interfaces which have earned praise in many circles for their user-friendliness. Recent versions of EZNEC contain a 3-D plot graphic that can be 'sliced' for select 2-D patterns. EZNEC also implements the NEC2/NEC-4 ground wave (RP1) output. EZNEC Pro will import or export files in .NEC format.

Nittany Scientific produces a Windows version of NEC-4 called GNEC. This program implements all or nearly all of the input cards of the complete NEC-4 input deck, thus permitting the use of caternary wires, helices, networks, and other core possibilities. Output capabilities include 3-D, polar plots, and rectangular graphs, as well a a large array of tabular reports. The spreadsheet and dialogue box interface is similar to NEC-Win Pro, described below under NEC-2.

NEC-2

NEC-2 is a highly capable version of the code which is in the public domain. It is restricted to antenna elements of a single diameter (although some software providers have introduced corrections for linear elements whose diameters varies). It cannot handle buried radial systems, although above ground systems close to the earth can be handled. However, it is equipped with the Sommerfeld-Norton high accuracy ground model for accurate modeling of horizontal wires close to the earth.

Nittany Scientific produces a Windows version of NEC-2 called NECWin Plus, which features a true spreadsheet geometry construction page set with design-by-equation capabilities. The program also offers stepped-diameter corrections, Gain Averaging Test, CAD (.DXF) file input, 2-D and 3-D plots and antenna views, and graphical outputs. The company also offers two other NEC-2 programs: NECWin Pro (NWP) and NECWin Basic (NWB). Both employ a spreadsheet geometry construction page, pull-down boxes for other antenna parameters, and Windows-style graphical outputs. In addition, NWP provides direct entry or importation of NEC model input 'cards' and provides a large assortment of available rectangular output graphics, along with other advanced NEC capabilities. Nittany-Scientific also offers a text for college classroom or self-study use: Basic Antenna Modeling: A Hands-On Tutorial

EZNEC, both in basic and professional versions, is available from Roy Lewallen. See the general description of EZNEC/ELNEC products under NEC-4 above. EZNEC 2, the basic version of the NEC-2 programs, offers 3-D plots with 2-D slicing, ground-wave output, stepped diameter correction, and numerous short-cuts to antenna geometry modification. Windows versions of EZNEC software are under development.

Antenna Solver is a product of Grating Solver Development Co. that uses NEC-2 as rewritten into C++ using dynamic array allocation. The user interface, graphical editing features, and data display capabilities allow analysis of antenna patterns, of near, far, and ground-wave fields, as well as currents and charge densities. A full-featured version of the program can be downloaded in the 'DEMO' mode for 30-day use, after which the purchase of a password will be needed to permanently enable the program.

Antenna Modeling Software

Poynting Software is making available the beta version of its hybrid NEC-2/UTD program 'SuperNEC,' which is implemented in C++. The program has a parallel execution option. It makes use of MatLab 5.2 to run the program and avails itself of MatLab's many input and output facilities, such as the use of MatLab language assemblies that users may add to or modify. A version (SuperNEC Lite) which is restricted to 300 segments and 3 GTD objects is available at a student price, and a demo is available at the web site.

EM Software and Systems produces a specialized user interface for NEC called 'WireGrid.' The program is a graphical user interface that automates the process of creating surfaces via wire meshes, while providing visual feedback on the structure, sources, networks, and field points. A demonstration version of the program can be down loaded from the EMSS web site.

Free

Expert MININEC

Before recent advances in speed and memory, it was not feasible to run NEC on a PC. Rockway and Logan developed MININEC, a Basic language adaptation of NEC for PCs. More recently, they have advanced the MININEC algorithms and code to overcome many of its initial limitations. The 'new' MININEC can handle sharp angles in antenna geometry directly (without segment length tapering) and handles antennas close to ground with much better accuracy. However, the MININEC Professional code (as well as the input/output interfaces) is a proprietary product.

EM Scientific offers several levels of Expert MININEC Professional, ranging from the basic level MININEC for Windows to MININEC Broadcast Professional. The product-level distinctions include the number of segments and unknowns available; advanced features of geometry, electrical, and solution description; and auxiliary calculations. These are all Windows products.

MININEC

The public domain MININEC code (version 3.13) is available with several commercial user interfaces, as indicated in these notes. For general antenna analysis that does not press its limitations, MININEC is a highly competent code. It handles elements of changing diameter directly, and with segment-length tapering, can accurately model a wide range of antenna geometries. However, horizontal antennas must be at least 0.2 wavelengths above ground for accurate results. Moreover, specification of ground conditions affects only antenna far field results, but not feedpoint conditions.

Orion of Canada offers a Windows95 32-bit version of MININEC, NEC4WIN, using a spreadsheet geometry input page, pull down boxes for other antenna parameters, and a pattern plotting output that includes lobe identification and bandwidth. In addition, the user can vary the height of the antenna without invoking a complete recalculation of the matrix for faster results. Recent or forthcoming upgrades include eliminating the maximum segment limit of standard MININEC, 3-D patterns, and optimization routines.

Other MOM and Antenna Software

Antenna Modeling Software Windows 10

NEC-BSC, the NEC-Basic Scattering Code (and its 'workbench') and other MoM-related software (including EM Surface Patch Code, Reflector Antenna Code, and Aircraft Code) are available (at about $300 per package) from the Ohio State ElectroScience Laboratory.

Nec Antenna Modeling Software

ASAP, Antenna Scatterers Analysis Program--originally developed by J. W. McCormack and made available as free downloadable software in the FORTRAN source code and PC executables by R. L. Cross--is a method-of-moment antenna analysis program with a 'more English-like' input system.

MOMIC, made available without cost by Professor Andrzej Karwowski of the Silesian Technical University in Gliwice, Poland. MOMIC is a Method of Momemtns Interactive Code for numerical modeling of arbitrary thin-wire radiating and scattering structures in free space.

Polar Plot is a program for the Windows 95/98 environment that uses the audio capabilities of the PC and a receiver to allow the user to generate a polar plot of his antenna. The program was developed for Windows by Bob Freeth, G4HFQ.

ASL Antenna Software Ltd of Great Britain offers a range of specialized antenna software.

The Seth Corporation produces MoM (including ENEC) and related software for EMI investigations.

The sources listed above have web pages for further information on the relevant software. Brian Beezley, K6STI, also has until recently offered a wide range of NEC-related software, as well as a Yagi optimization program, a terrain analysis program, and DSP software. Contact the author via mail, since the most recent e-mail address (k6sti@n2.net) may no longer be active. The K6STI NEC-2 program NECWires now has an independently-developed Windows interface called Win-ni (developed by Pat Wintheiser), available through The (Unofficial) NEC Archives.

ACES

The Applied Computational Electromagnetics Society (ACES) is perhaps the professional focal point of advances in all forms of electromagnetics codes and related mathematical models. It holds an annual meeting on the west coast in March with a very full and varied program. Antenna

The Unofficial NEC Archives

Hf Antenna Modeling Software

The (Unofficial) NEC Archives are maintained by Ray Anderson, WB6TPU. Formerly, this collection of NEC-related software has been available only via FTP. However, the entire contents are now accessible via the web. They include many source codes for NEC and for pre- and post-processing of NEC, along with some sample input files. Another valuable website of NEC-2 information is maintained by Peter Richeson.

This listing is necessarily limited. However, the indicated web pages will lead you to other information on details, specifications, related developments, and a more complete understanding of the rapidly expanding field of electromagnetic modeling. For a more complete account of some of these sources, see QEX, March-April, 1998, pp. 47-50. However, as with all software information, development efforts quickly outrun written accounts.

Antenna Modeling Software

Updated 03-05-00. © L. B. Cebik, W4RNL. Data may be used for personal purposes, but may not be reproduced for publication in print or any other medium without permission of the author.

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