Questions tagged [antenna-modeling]

Use for questions about using antenna modeling software to simulate an antenna system and determine its gain and radiation pattern.

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2answers
84 views

How to make ELF-ULF antenna myself?

I want to check the EM pulse between 3HZ-3kHZ with N9041B UXA Signal Analyzer,it seemed the only antenna I can use is Aaronia MagnoTRACKER,but the price is not affordable. Then I plan to make ELF-ULF ...
2
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1answer
39 views

How Accurately Does NEC-based Antenna Software Calculate Vertical Monopole Antenna System Radiation Efficiency for "Far-Field" (Only) Conditions?

A common belief among amateur radio operators is that the radiation efficiency of a vertical monopole driven against the Earth is much less than that of an elevated, horizontal dipole of the same ...
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2answers
615 views

Modelling a "fan dipole" or "fan inverted vee" using EZNEC - unexpected result

I plan to put up a "fan inverted vee" but for various reasons I will not be able to take it down, adjust wire lengths, put it up, test, etc: I will basically have to cut the wires, put it up and leave ...
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1answer
31 views

4nec2: simulating the effect of walls over the far-field pattern

I live at the 15th floor and am interested on a pair of window-mount antennas for the 40 meters band: a top-fed vertical; and a loaded monopole, which I've already used with pretty decent results. I'd ...
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0answers
29 views

Magnetic and Electric Wall in HFSS

I'm new to RF engineering and I want to ask how to draw magnetic and electric wall in HFSS software? I know magnetic Wall means open circuit in circuit model and electric wall means short circuit, but ...
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1answer
70 views

Where can I find London borough outlines for SPLAT!

Splat seems like it's a great tool for modelling what RF coverage I should have. It can create a nice circle around me, after I download topology data from USGS, namely SRTM-1. But when the coverage ...
0
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1answer
28 views

4NEC2 shortening factor "x"

I read on pg5 of Antenna Simulation with 4NEC2 about shortening factor "x". It is very specific and I can't figure out how to use it in a general nec file. It sounds like SY x=0.907 in the ...
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1answer
32 views

How to model a curved element in 4NEC2

I am in kindergarten with 4NEC2 and trying to model a Gray-Hoverman TV antenna. I have someone else's model and understand most of the file parameters. I have added VHF elements that have S curves at ...
0
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1answer
34 views

Software to model autotransformer matched end fed dual band, 4nec2?

I have several ground independent dual band antenna of different makes, but they all have the same type of matching circuit to make them ground independent / radial-less and match say 5/8 elements, ...
3
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1answer
125 views

How to simulate two antennas in 4nec2

I need to simulate 2 helix antennae placed side by side, and see the resultant radiation pattern. But after adding the second antenna with a separate and when I try to simulate 4nec2, only simulated ...
2
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1answer
146 views

Mutual impedance of two parallel dipole

Good Morning all, I want to calculate the mutual impedance of two parallel dipole. The first hypothesis is to assume that the dipole 2 is in open circuit, nothing difficult here I knew how to do it ...
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0answers
257 views

4NEC2 radials & grounds

Teaching myself 4NEC2 and have most of it under control, which is good. Regarding radials & grounds, i've been learning the "rules" NEC(2) has, summarised below. 4.1. Free space. In the ...
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1answer
110 views

Modeling a multiband Yagi in 4NEC2?

I tried to model a multiband yagi. I added radiators for 10-15-20M, and reflectors spaced .15 wavelenghts away. This gave a nice result with three sharp dips in SWR in the 10-15-20M center frequencies....
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1answer
233 views

How to model my rooftop vertical on 4NEC2?

A few months ago I built a coil loaded vertical, and put it on my rooftop. My roof is made of corrugated metal, so I connected GND to it, to act as a ground plane (or is it a counterpoise?). With some ...
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5answers
5k views

Does mounting a ground plane antenna upside down change the takeoff angle?

A typical gain pattern for a quarter wave ground plane antenna is: Image from a similar question and see watermark. For a situation where the signals of interest are below the antenna in elevation (...
5
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2answers
486 views

Modelling a folded dipole

I am looking at using NEC to model a $0.5\lambda$ rectangular folded dipole, for closely spaced larger sides (choosing a separation of $0.01\lambda$). In Antenna Theory, Analysis and Design by ...
3
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1answer
139 views

Do Far-Field Radiation Patterns/Gains of NEC Software Accurately and Always Show the E-M Fields "Launched" by Vertical Monopoles?

Judging from posts on the Internet, this belief commonly is considered to be valid. But what is the correct answer?
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1answer
421 views

ADS Simulation: How to model an antenna in a simple rectifier circuit?

As titled, I'd like to explore the output power of a simple diode-based rectifier circuit, excited by an antenna (assumed to be 50 ohm impedance). Please give me some advice as to how to do this. It ...
3
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1answer
349 views

Mathematica notebook for NEC2 (NEC, Numerical Electromagnics Code)

Are there any open source Mathematica notebooks that interface with NEC2? I am primarily interested in plotting the NEC2 results from Mathematica.
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3answers
5k views

How to produce a NEC antenna file (and what software to use it with)?

So I'm really trying to get to grips with antenna radiation patterns, and more importantly things that are to close to the antenna that might interfere. I've downloaded Qantenna and 4NEC2 to try and ...
8
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2answers
768 views

Simulating two antennas (transmitter and receiver) using 4nec2 tool

I am trying to find near field mutual coupling affects between two antennas - one being transmitter and other being receiver. The receing antenna is fed with very little voltage (I think, if I don't ...
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1answer
1k views

Is there a 4:1 current balun model for 4nec2?

I don't seem to be able to find the data to enter a 4:1 current balun in the 4nec2 software. Has anyone found or written one? I am building a 75 Ω fed OCFD and need to model the radiated patterns, ...
3
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2answers
620 views

Antenna gain vs. radiation efficiency in 4nec2

I'm trying to evaluate HF antennas for low angle performance to pick from a list of designs that will fit in my limited space. I'm using 4nec2 to simulate them and compare the patterns. When your ...
4
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1answer
927 views

Correct number of elements in 4nec2 antenna simulation

I am designing a 1.25-wavelength dipole antenna with the 4nec2 software. What I noticed is that the input impedance of antenna is changing greatly when I change the number of segments. How many ...
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2answers
980 views

4NEC2 - Radiat-eff. vs. Radiat-power

In the output from 4NEC2 the input power is 100 W. On the left, in blue text, is Radiat-eff. which equals 15.41%. On the right is Radiat-power which equals 94.88 W. I would expect either the first ...
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1answer
155 views

4NEC2 - Antenna outside Pattern

I am very new to 4Nec2 and need to do a simulation of a half-wave dipole antenna for 433 MHz. I've read a couple of tutorials and I understand most of it so far, still, my simulation doesn't make ...
4
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2answers
152 views

Basic antenna matching theory?

I'm fairly new to antenna matching, other than having built a base loaded vertical. I'm also new to EZNEC and I tried to simulate an horizontal loop. I arbitrarily chose a 10x10M loop, so I added 4 ...
2
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1answer
267 views

How do I simulate a receiving antenna in EZNEC simulation tool?

I have a situation where I need to find receiving antenna impedance when it’s $\lambda/2$ distance from the transmitting antenna. Both are dipole antennas. Is it possible with EZNEC?
5
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1answer
100 views

How to model passive elements when simulating an antenna?

So I started writing an antenna simulator program to design antennas for my needs. To calculate the electric field vector at every point, I split the active element of the antenna into a large number ...
2
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1answer
1k views

How do I specify that wires are connected in 4NEC2?

I've been trying to get acquainted with the 4NEC2 antenna modeling program. Perhaps this is obvious, but it's not clear to me that wires with one end in the same place are connected. I'm attempting ...
1
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1answer
653 views

Raising height of inverted V by 2 meters

Now that I have a working G5RV Jr. and have had some good luck with DX (Croatia and Venezuela on 20m, Morocco on 40m from Michigan at 100w output), of course I want to mess with the configuration. It'...
2
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1answer
78 views

How to consider the influence from the PCB that a small antenna is mounted on?

The small antenna itself has an $S_{11}$ of -3 dB around MICS band (verified with simulation and network analyzer). In application, the antenna is mounted on a transceiver PCB of 30*15*0.8 mm which ...
9
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1answer
168 views

Antenna modeling on non-uniform terrain

I'm interested in modeling the radiation pattern of wire antennas for hf before I invest the resources necessary to erect the antenna. I'm familiar with tools such as 4nec2, but from what I can tell ...
2
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1answer
105 views

Convert NEC antenna file to .out-file for Wattwächter

I've just wrote a NEC Antenna file of my longwire with xnec2c on Ubuntu. To calculate protection distance with Wattwächter, I need an .out-file. Protection distance means the safety distance for human ...