Free/Open Source Antenna simulation tools?

[reagle]

So it appears pros use tools such as HFSS and CST  that cost $$$. What do hobbyists use if they have a desire/need to simulate a PCB antenna for say sub 1GHz frequencies?

[tipofthesowrd]

openems.de is quite good. But heavily based on script language.
I've not come across an open source 3D em simulator which also has a very detailed and functioning 3D CAD.
Can't have your cake and eat it

[MSO]

Have you tried the EZNEC free demo?  It has some limitations but might be able to do what you're looking for.
http://eznec.com/demoinfo.htm

The ARRL Antenna Book also includes a copy of EZNEC with fewer limitations than the demo copy.
http://www.arrl.org/arrl-antenna-book

 

[Ivan7enych]

Try MMANA, it's free and does a good job, but UI is not so easy.
http://gal-ana.de/basicmm/en/

[reagle]

Awesome, thanks! I now have a few choices to play with- sure beats copper tape and eXacto knife I've been using as my toolset

[Theboel]

if You decide to use MMana and when You need to know the gain prediction from MMana is not so accurate especially when Your antenna close to ground (in term of wave length)  You can recheck it use NEC-2 for MMana software:
http://www.qsl.net/ua3avr/
overall I have no issue to use MMana for 10 years start from original MMana write by Makoto Mori, JE3HHT

[hendorog]

Feko, which I've downloaded but barely used. Seems very powerful, free key available after registration, but with pretty strict limitations.
https://www.feko.info/

Another free NEC version - pretty easy to work out and no limitiations AFAIK. I haven't used for PCB type antennas though, it might not support them.
http://www.qsl.net/4nec2/

[PP7BB]

ELMER - it is free simulation tool, not only for magnetic field.  It is multiphysical simulation software managed by CSC - IT Center for Science (CSC) in Finland . I havent tried it yet, it is too complicated for me.

Here is link to Elmer:
https://www.csc.fi/web/elmer

And its  forum :
http://www.elmerfem.org/forum/

[thewyliestcoyote]

NEC2 is freely avalible. There is a port of NEC to C++ and has some wrappings like python.

https://github.com/tmolteno/necpp

FDTD is a simple enough concept. It is a very good learning experience to write and play with. If you are not up to that there is this.

http://openems.de/start/index.php

In short is there is nothing that great like CST or ADS or it pains me to say this HFSS.

[reagle]

This is becoming a rather handy reference. I wonder if Dave should make it a sticky?

[Kelbit]

I previously posted in another thread about this... copying here:

I have been searching for a good free 3D field simulator for a while. It's getting to the point where I'm seriously considering writing my own FDTD engine.

A quick summary of the options that *are* free:

NEC-2 is a public domain Method-of-Moments (MoM) simulator suitable mainly for wire antennas and some planar antennas which do not rely on dielectric structures (so no patch antenna simulations). It was originally written in the 1970s at Lawrence Livermore National Lab, so the interface leaves much to be desired. It's a command line program that takes a text file input, where each line of text represents an 80 column punched card in a card stack. There are a few graphical interfaces available (4NEC2 is the most popular free one) but they are all pretty old. There's definitely a demand for a modern 3D CAD type frontend, if anyone's looking for a weekend project.

OpenEMS is a free FDTD (Finite Difference Time Domain) simulator suitable for a wide range of computational EM problems. As an FDTD package, it will be a lot more memory heavy than a FEM or MoM simulator, but RAM is cheap these days. The main drawback is the interface - there's no UI, rather, the software is used programmatically through a MATLAB/Octave frontend. Again - making a UI would be a great weekend project if anyone's looking. If you can handle the lack of UI, this package is the best truly free option right now.

MEEP is another FDTD package. Looks more like it's geared towards photonics applications, although the physics are the same. Again, no UI. The main drawback I can see is that as it's more of a physics research package it doesn't include postprocessing features helpful for EE, namely s-parameter output and far-field radiation pattern computation - you'd need to write your own postprocessor.

EmGine is another FDTD package. Unlike the others, it has a UI. Unfortunately, development has stalled and apparently it's difficult to run on Windows on the latest Python. Also, the license prohibits commercial use.

Sonnet Lite is the free version of Sonnet, which is a planar EM simulator based on the Method of Moments. Very similar product to Agilent Momentum that's included in ADS. It's good for simple printed transmission line structures like microstrip, hybrid couplers, and filters. You can also do patch antennas with it, but you can't view the far-field patterns unless you buy the full version, so it'd be good for tuning return loss only.

FEKO Lite is the free version of FEKO (registration required). FEKO is a professional EM field sim comparable to HFSS or CST which has a big list of solvers: MoM, FEM, FDTD, and UTD, as well as several hybrid MoM-FEM solvers. It's got most of the features of the full version but the mesh size is heavily restricted. Still, you can solve small problems with it, like basic microstrip antennas.

Basically, there's a demonstrable need for a user-friendly 3D high frequency electromagnetics simulator in the open-source space, but nobody's picked it up yet. Of course, if this is for personal use, you could "acquire" a "time unlimited evaluation" of HFSS.

[SilverWingedSeraph]

I'd suggest taking a look at XNEC-2C. I made a video about its use: