From owner-qrp-l@Lehigh.EDU Thu Mar 13 08:13:31 1997 Received: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.7.6/8.7.1) with ESMTP id IAA22898 for ; Thu, 13 Mar 1997 08:13:30 -0500 (EST) X-Received-x: from fidoii.CC.Lehigh.EDU (fidoii.CC.Lehigh.EDU [128.180.1.4]) by oucsace.cs.ohiou.edu (8.7.6/8.7.1) with ESMTP id IAA22898 for ; Thu, 13 Mar 1997 08:13:30 -0500 (EST) Received: from Lehigh.EDU ([127.0.0.1]) by fidoii.cc.lehigh.edu with SMTP id <35430-21215>; Thu, 13 Mar 1997 08:12:55 -0500 Received: from nss2.CC.Lehigh.EDU ([128.180.1.26]) by fidoii.cc.lehigh.edu with ESMTP id <35389-15580>; Thu, 13 Mar 1997 08:12:00 -0500 Received: from utkux4.utcc.utk.edu (UTKUX4.UTCC.UTK.EDU [128.169.76.11]) by nss2.CC.Lehigh.EDU (8.8.5/8.8.5) with SMTP id IAA29611 for ; Thu, 13 Mar 1997 08:11:53 -0500 Received: from localhost by utkux4.utcc.utk.edu with SMTP (SMI-8.6/2.7c-UTK) id NAA10217; Thu, 13 Mar 1997 13:11:40 GMT Message-Id: Date: Thu, 13 Mar 1997 08:11:39 -0500 (EST) Reply-To: cebik@utkux.utcc.utk.edu Sender: owner-qrp-l@Lehigh.EDU Precedence: bulk From: "L. B. Cebik" To: "Low Power Amateur Radio Discussion" Subject: Antenna Modeling Programs MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-To: towertalk@contesting.com X-Cc: QRP-L List X-Sender: cebik@utkux4.utcc.utk.edu X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN Status: RO I have added a page to my site with links to some of the main web pages of antenna modeling software providers. I thought the basic info might interest members of the list, so I added the links visibly to the text below. I hope the info is useful to some. -------------------------------------------------------------------------- Antenna Modeling Some Notes on Antenna Modeling Programs 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 antenna modeling software providers. NEC-4 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. (http://www.teleport.com/~w7el/) At present, I know of only one source of commercial software for NEC-4: Roy Lewallen, W7EL. EZNEC Pro 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 for DOS and employ similar user interfaces which have earned praise in many circles. 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. (http://www.nittany-scientific.com) Nittany Scientific produces a Windows version of NEC-2 at two levels: 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. MININEC "Professional" 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 is a proprietary product. (http://www.sierraweb.com/emsci/) EM Scientific offers several levels of MININEC Professional, ranging from the basic level MININEC for Windows to MININEC Broadcast Professional. 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. (http://www.cam.org/~mboukri) Orion of Canada offers a Windows-based version of MININEC, 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. Other NEC and Antenna Software (http://www.demon.co.uk/asl/) ASL Antenna Software Ltd of Great Britain offers a range of specialized antenna software. The sources listed above have web pages for further information on the relevant software. Brian Beezley, K6STI, also offers a wide range of NEC- related software, as well as a Yagi optimization program, a terrain analysis program, and DSP software. ACES (http://www.emclab.umr.edu/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. 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. -73- LB, W4RNL L. B. Cebik, W4RNL /\ /\ * / / / (Off)(423) 974-7215 1434 High Mesa Drive / \/ \/\ ----/\--- (Hm) (423) 938-6335 Knoxville, Tennessee /\ \ \ \ / / || / (FAX)(423) 974-3509 37938-4443 USA / \ \ \ \ || cebik@utk.edu URL: http://funnelweb.utcc.utk.edu/~cebik/radio.html