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