4nec2\exe” folder, in your Word or Wordpad text editor. Other recommended sources for NEC related informations are the Nec-2 and Nec-4 user-manuals and . 4NEC2 is a freeware antenna simulation software program. The program can be used to model an antenna, and then determine through. Antenna Modeling With 4NEC2. Presented to HOTARC. By Craig Weixelbaum. May 22, Basic Modeling Approach using 4Nec2. The goals of this
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The results of the AGT are interpreted in this way [Ref.
The understanding of the coordinate system employed in a simulation program is fundamental both for the design of the models and to correctly evaluate the results of the simulations. You have to select View, then, select manua field pattern.
They must be placed at a height over the ground of at least one fifth of the working wavelength: Folded dipole with resistive load model. Normally, the results will be similar to those one may find in the textbooks.
EA4FSI-28T1 – Technical Articles
Be prepared to take some time learning how to take advantage of everything this modeling program has to mznual.
In order to avoid errors, it is of interest to observe the following general rules while designing simulation models: After thousands of optimizer iterations, It looks pretty good. V The data information returns, after running the model, on the main page, antenna efficiency and radiated power relative to fed power.
This free software does everything and more the commercial versions do! But thanks to this product I now have a very good antenna that took manyal less time and money than any other antenna project to build, install and tune.
The convergency test must be repeated in a representative set of frequencies from all the working band of the antenna. The Z axis will represent the height of the antenna over the ground plane XY. Let Zs be the height of the wire over the ground.
All the words in the world don’t suffice to say: American Radio Relay League. With the fast ground type, NEC-2 uses a method based on complex reflection coefficients. In this manner I can tell if I need a 4: If it is considered that the transmission line may have influence on the radiation of the real antenna which is being simulated, it is possible to try to create a model of the line in some particular cases, such as with the parallel transmission line.
They must be placed at a height over the ground of at least one fifth of the working wavelength:. For each case, specifications are provided regarding whether the wires 4nec22 touch ground or not and in the negative case at which height over ground must be placed.
It also includes state-of-the-art 3D visualization and a drawing style structure editor. This displays the antenna and models its output.
When I 4bec2 ran this program I almost put it in the too hard basket. The following angles are defined: In the case of wideband or multiband antennasmake the convergency test only with configurations of number of segments per wire laying within the limits computed in the previous sections.
EA4FSIT1 :: Notes on antenna simulation using NEC-2
By getting the ratio between threory and real, I could compensate for things like roof attenuation, velocity propogartion of insulated wire, complex surronding objects, etc. The MININEC ground model assumes a perfect ground for the computation of the currents and changes to a dielectric ground for the computation of the far field patterns ground without losses.
Example, for my OCF, if I desire to know the 50 ohm impedance response, then, I specify a ohm characteristic impedance for computing SWR and assume that I have a 4: Antennex Monthly Columns – Antenna Modeling The optimizer is just plain awesome and has saved me so much time and generates significant improvements on all my designs.
The notes are not oriented to be a guide to work with the different available programs based on this algorithm, but they pretend to be a quick reference for users already initiated on its use. Once you start with just a basic dipole, moving on to base-fed verticals, Yagis, quads and other geometrically complex antennas becomes much easier to model.
It’s the most fun you can have without laughing! Press the space bar to toggle between side and top view. If two wires of different diameters are close of each other, despite the fact that their segments are aligned, errors in the computation of the antenna gain and its input impedance may be obtained, especially in the part of the reactance [Ref.
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In order to define a wire of length Lh in NEC-2, it is necessar to specify the coordinates of the two points delimiting its ends, the conductive material employed, the wire diameter Dh and the number of segments which will form the wire.
Saves me wasting time physically testing poor configurations. My spring antenna building plans are pretty well set, thanks to Arie and LB sk. The azimuth angles are measured clockwise from the Y axis towards the X axis. Coordinate system used in 4Nec2. So, if you define a LC network in the model, the code will compute loss. Then, if that variable length for example needs changing, it can be changed in one place in the model much like a software program.