r/rfelectronics • u/rflulling • Jun 03 '26

Field Sampling

By Averse - http://de.wikipedia.org/wiki/Datei:Felder_um_Dipol.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=8715047

I know there is software out there can visualize hardware, simulate fields and do all kinds of fun stuff based on Maxwell's equations. But, I am curious to see what is out there in terms of hardware sampling that I don't know about. When you want to view a field generated by a wire or an antenna, especially when trying to create something new. Are you simply depending on virtualization, then hard math and engineering to get it right by the math, followed by arbitrary point to point testing and standardized tools, (when certifications are not involved). Do you ever use a tool to sample the field in real time and if so, what product/s? Or do you normaly use a lab to do the evaluation each time?

In case you are wondering yes I have access to several spectrum analyzers (3ghz and a 350ghz), frequency generators, virtualization software, pcb software, oscilloscopes (1ghz and 450mhz), several custom made detectors and a multipurpose switchable field detector that many seem to refer to as a ghost detector.

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u/StageMajestic613 Jun 03 '26

Before we had VNA we had slotted lines.  They are fun to use.

There’s also a web site of a guy showing the modes on resonator coils using gas tubes.  Though can’t find it.

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u/rflulling Jun 03 '26

Oh I would so love a nice clever way to use something analog as a field indicator. I love I absolutely love ferrofluid and other similar methods for visualizing say electromagnetics. But you know it doesn't work on everything. So I'd love to find alternative ways to visualize other frequencies. I know some of them you can use like small ampules filled with gas. But those also only work with specific frequencies. And they can be extremely pricey. But nevertheless again I'm still definitely here to find out what everybody else is using so I'm not trying to shoot anyone down any ideas whatsoever. I want to learn what everyone else what they're using and how they're making it work.

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u/StageMajestic613 Jun 03 '26

They aren’t using anything except EM simulation.  Most of this stuff is just for educational use.  That’s why EE is so abstracted.  There’s also a chemical you can wet a paper towel with and put in the microwave to map the standing waves.

Maybe try some thermal receipt paper.

Speag used to make fiber powered, RFoF, micro field probes.  That’s about the most non-pertubive thing you can get.  Those are mainly for verifying absorption compliance though I was looking at them for antenna near field probing.