Electromagnetic waves are in a sense a bit mysterious: You cannot see them, not smell nor touch them. Nevertheless, the propagation of electromagnetic waves is greatly influenced by surrounding objects and media. The performance of an antenna, and in particular its radiation pattern, is therefore difficult to visualise, interpret and measure in an objective way.
Additionally, there are (almost) no closed-form formulas for designing antennas. Antennas are usually designed in an iterative trial and error process, often comparable with Darwinian organic evolution, in which certain aspects of partially successful designs are combined in the hope of producing a more successful design. Antenna synthesis software based on this principle employ, what is called, a genetic algorithm (GA). There is little need to say that the alternative to this, which is: repetitive building, installing and measuring antenna design variations is very time- and material consuming.
Both problems are to a great extent overcome with computer-aided antenna modelling. As a bonus, you will be eager to try out more design variations, often resulting in better performing antenna designs. The reiterative modelling of antenna variations will furthermore provide you with insights that are difficult to gain in a different way.
4nec2 is especially unique in the sense that it is the only freely available amateur antenna modelling software offering antenna synthesis capabilities.
ON4AA with W7EL,
author of EZNEC
Both EZNEC and 4nec2 are also truly unique in employing for the modelling of wire or aluminium tubing antennas above «real» ground in both the near- and far-field of the antenna. Apart from antenna synthesis capabilities, 4nec2 adds to this some extras in the form of surface patches, support for inclusion of the surface-wave component in the far-field results and last but not least, the best propagation prediction engine on the face of this planet.
Other non-NEC-2(4)-based codes like MININEC etc. model the ground only as a perfect conductor right underneath the antenna, in the near-field. This simplification leads to only very approximative values for feed point impedance and resonant length.
Apart from those mentioned here, there are many more codes around for a huge variety of different antenna configurations and purposes. If you want to learn about more modelling codes written by professional antenna engineers, you can nose around on the site of the Applied Computational Electromagnetics Society (ACES).
Most important of all when using antenna modelling software, is knowing how to use any particular software code. The modelling and segmentation of structures for which the code was not designed, will certainly produce erroneous results. To quote one of my former professors:
«Bullshit in = Bullshit out!»
(Now you know the kind of people that lectured me!)
Modelling simple antenna configurations in a real-world setting is not as difficult as it sounds. I learned the tricks of the trade, by focusedly reading the EZNEC manual, paying attention to geometrical limits and potential pitfalls. Similar 4nec2 manuals are available from the 4nec2 website. However, both programs are based on NEC. Once you are accustomed to one of these programs, getting your grips around the other happens rather intuitively.
With the advent of the web era, there was also the antenna modelling website of antenna-guru L. B. Cebik, W4RNL (SK). It was the most complete, useful, scientific and knowledgeable amateur radio web site on the subject of antenna modelling. For any serious ham or antenna professional it truly was must-read material. However, where Cebik's site used to be an open and free access place to learn, an unscrupulous entrepreneur vulturously converted the site to a closed commercial site within a month after Cebik's passing. This was most probably not what Cebik had in mind when he ceded his copyright to his hosting provider... It was Cebik's vain attempt to perpetuate his knowledge. Nevertheless, Cebik's site inspired many hams -including myself- to set up a little web site of their own, forever doomed to be overshadowed by Cebik's monumental achievement.whose work or who's work how much business permit how far science has come what tech would look like why business analytics why tech stocks are falling who design central park where to manufacture my product when teaching systems and routines to a group where project nasa why teaching is important when project is not ready gif how solution is prepared how much start up how much start up capital is required to start a business where workers may get the shaft how much development length of steel reinforcement an entrepreneur whose business is anchored on technology how long science museum london what is the most popular technology used today where to set up signature in outlook where equipment operating at 1000 volts who design nazi uniforms how much solution for hoover carpet cleaner what business to start in 2022 how many product placements in he's all that where technological advancements which startup is best how many teaching vacancies in florida how many products does coca cola produce globally which engineering major should i choose how london bridge fell how business works where to launch model rockets how much system 8 powerball why product marketing where to buy clothes from manufacturer why teaching to the test is bad where company is a sham why solution focused therapy when equipment is purchased for cash quizlet how much workers comp pay why technology is important in our life workers who have previously who engineering consultant how much equipment has lost how start up which device is i'm a window an example of where did we come from science how to roadmap an essay how startup equity works on start up synonym how community solutions startup folder where is working solutions located from where to start business how many management courses are there why project based learning is important how long project management certification how much teaching english taiwan how many solution does the system have how much solution in vax platinum which science is the easiest when manager praises you who solution for covid 19 where to solve word problems how much business class cost when startup become unicorn who engineering consultant which equipment is used to administer phentolamine what workers found in giant snake how many london airports are there where science ends religion begins when management is the problem why tech investment banking how to device manager when is start up season 2 roadmap when do restaurants open when business taxes due 2022 whom company how often to use newa device tattoo designs what science is taught in 9th grade how often business continuity plan be tested how workers compensation works what workers want 2022 why workers join unions how often set up guitar roadmap how to create when science was wrong when engineering and administrative controls what project management whom pronouns whom may concern how much science is in nursing which london airport and terminal tool why technological advancement is necessary in india who tech transfer how many entrepreneurs which startup stocks to buy where does technology comes from when device is in vr how often does technology improve why products are discontinued from where to start teaching english why startup need funding what two things must you check before using any equipment how manufacturing costs where does an entrepreneur work how much company in tata group where's the science museum how much startup capital is needed is a part of how much entrepreneurs earn in india how many design styles are there how solution set why science of reading which product roadmap who project in ku