802.11 Attenuation Conductive setups
Last Post: February 9, 2007:
Does anyone know of any expert source (book, website, etc.) on setting up a SISO conductive setup? I need to research various attenuators, splitters, combiners, couplers, reverse polarity connectors, and RF cables. I also need to account for antenna diversity on some AP's & STA's. First I need to identify what I need before spending the big $$$ on parts. Simple setups are fine as I'm not doing any performance testing; mostly protocol conformance & analysis. Once I get my head wrapped around this then need to forge ahead on MIMO conductive. Unfortunately, I'm not a RF engineer.
Seems all I need for a start is a few pairs of shielded RF cables, the right connectors/adapters, variable 1dB stepping attenuators, and some splitters so I can cable in a RF sniffer. I guess some copper tape might help to plug the leaks. Alittle leakage though I'm expecting.
Thoughts? Any hints much appreciated.
Um... What? :)
Seriously, what is SISO? I googled it, but I'm still lost. What are you trying to do?
I was wondering if it meant Single Input Single Output versus MIMO? But, I am not sure how that relates to the questions.
Sorry, should have specified. Yes, Single Input Single Output as in 802.11bg without diversity. For starters I'm just going with a AP having one antenna and a STA with only one antenna. Unlike MIMO with three or more antennas or "SIMO?¡é?€??: one transmit antenna and two receive antennas.
This simple diagram may help clarify what I'm trying to do. I'm lost on identifying the correct RF components due to number of options available based on what one is trying to achieve. My purpose is to isolate the test environment from the surrounding wireless networks to do basic protocol analysis.
MIMO Compared to SISO
I am not an EE by a long shot, but sounds like you need this:
That requires some test lab that can be quite expensive, I think.
Nice share of the decode BTW, lots of parameters! You have it as a protected file...SMART! 8)
Makes sense after the diagram, thanks for including that. Initially your biggest headache will be the Faraday cages or enclosures. This link is an example of what is available as well as material that you can use to make your own. I was not able to ascertain how big the enclosures would be from the diagram.
I also use the trick of enclosing RF conductors/coaxial cable in normal electrical conduit and boxes with a very good earth ground, that should remove any stray RF from skewing the results.
You will get some radiation from the other cables entering the enclosures but that can be minimized as well by good grounding.
As usual I resort to my amateur radio experience, and have listed two links. The first one is kind of a back handed approach as Hams are concerned about EMP and keeping equipment going, but what keeps EMP out will also keep RF in. The second link refers to isolating RFI which again is kind of looking at the issue in a different light but the principles and technology is identical.