measure evm

[vatican]

what card is available to measure EVM @ approx. 5 GHz ???

[JÞB]

Just what specific metric of the European Vaccine Manufatcurers (EVM- google it) do you need to measure, and why so fast?

[Ray.R]

EVM : Error Vector Magnitude

You'll have to give WAY way more details.

Are you using an instrument such as a Spectrum Analyzer? (R&S 🙂  Agilent 😐 Anritsu 😞  )  <= ease of programming EVM

Then you need a GPIB card.. Or you may be able to communicate with them using serial, USB or Ethernet, depending on interface.

If you are looking for a "card" that you plug into your PC to do an EVM measurement at 5GHz...  hummmm...  I don't think it's readily available or it will certainly not be cheap.

Message Edited by Ray.R on 11-10-2009 09:58 PM

[smercurio_fc]

Well, technically, the user didn't say the signal was 5 GHz. He just wants to measure it that fast. So, you could get an overclocked machine running at 5 GHz and calculate it really really fast.

[Ray.R]

Technically, you're correct.  There was no mention of what the 5GHz meant.

As long as it is not 5 billion samples per second 😮

😉

[Ben]

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Ray.R wrote:

Technically, you're correct.  There was no mention of what the 5GHz meant.

As long as it is not 5 billion samples per second 😮

😉

---

Not for a full second! But for NDT (non-Destructive Testing) we use hardware to control tha acquistion in very short bursts.

G-Story time!

This was one of those trips that start out with my phone ringing on a Friday night and my boss saying "Ben, we need you to...". So a customer was nearing a deadline and the code was not running. They did not want to take the other compnay off of the project (politics!) so I found myself co-developing with the "Other company". The other developer simply did not understand LV, (his own words) but that did not stop him from trying to run his mouse the same time I was running my track ball. There was more than once that complete section of a diagram got dragged form one place to another (I was stepping outside regularly to scream). I managed to stop him by shutting of auto-tool select. Most of my work was done after hours when he wasn't around.

So we were putting together an inspection system for railraod wheel where we used a multi-GHz signal to ping the whell as it rotated under our sensor head and dpending on the detection of internal flaws the whee was acepted or rejected. So after two week of work that week the system shipped on time. After a follow-up trip by one of my co-workers they sent me a gift to acknowledge that adveture. I now own a 10" section of a railraod wheel neatly cut and polished. Try to buy one of those at a model railroad swap meet.

Ben

[Dennis_Knutson]

Link to EVM explanation and the RF Vector Signal Analyzers that measure it (up to 6.6 Ghz).

[Ray.R]

Thanks Dennis,

I was not up to date on the latest NI RF hardware.  Up to 6.6 GHz.  Nice..

The price tag is to be expected. ~$30K + PXIe chassis.

Add a power meter and you have (almost) a Spectrum Analyzer + VSA.

Good story Ben.

I'm sure that has become a piece of collection for you. 

Message Edited by Ray.R on 11-11-2009 11:59 AM