off-the-shelf RF sensors for WCDMA modulated signals

[razvanel]

wcdma low power sensor

Can anyone point me in the right direction as to where I can find off-the-shelf RF sensors for WCDMA modulated signals (3G incoming and outgoing calls) ?

∞ thanks

 

[vfone]

Re: WCDMA sensors

Probably the best and easiest way to sense WCDMA signals is to use one of the True Power RMS Detectors from Analog Devices, ADL5501/2 or AD8361/2/3.
Can ask for samples direct from ADI.

https://www.analog.com/en/rfif-components/rms-detectors/products/index.html

 

[razvanel]

Re: WCDMA sensors

thanks for the reply. I actually wanted an off-the-shelf product, no matter how costly. Just need a place to start looking.

I am assuming that for that chip i have to make up a circuit that i might not have enough time to conceive...right?

i just need it to output an analog signal that i can amplify and convert to digital. any help is appreciated either way.

 

[razvanel]

WCDMA sensors

no one knows an off the shelf product that detects rf signals..?

800MHz - 2100MHz range.. high sensitivity i guess(to overcome the low power of the spread of the WCDMA signal)

thanks,

Raz

 

[vfone]

Re: WCDMA sensors

OK. You mentioned, no matter how costly. Buy this USB plug & play RF Power Sensor from R&S, which has impressive sensitivity and dynamic range.

**broken link removed**

 

[razvanel]

WCDMA sensors

thanks, i sent them an email to see if they have something slightly more rudimentary. i really just need something to detect the RF signal and output a proportional DC voltage...

it seems like the Rhode-Schwarz is a bit of an overkill here. If anything else comes to mind, please let me know.

 

[vfone]

Re: WCDMA sensors

Cheaper option would be to buy from ADI an Evaluation Board for one of those True Power detector chips. (approximately $100).

https://www.analog.com/en/rfif-components/rms-detectors/ad8361/products/product.html

 

[razvanel]

WCDMA sensors

you know what, i actually called them up and although they will look into it and try to come up with a recommendation, they did say that these chips pick up all the signals on the band and come up with an RMS measurement...that's no good.

in WCDMA, all signals are mashed up into this 5MHz band and coded differently, so that the base station and the handset use the same code to be able to filter the messages, and understand each other. now, i need this product to just sense when the phone near to it is making or receiving a call.

doesn't this make you think that this chip will just keep showing output just because there's other ppl communicating on that 5MHz lump of band? could this be smth related to sensitivity? so that it can only detect the phone nearby...

 

[vfone]

Re: WCDMA sensors

Now I find that you are not looking for an RF sensor, but you are looking for a narrow band and selective receiver, which is a totally different story.

 

[FvM]

Re: WCDMA sensors

i need this product to just sense when the phone near to it is making or receiving a call

Without a specification of near, your question can't be answered.

The range of solutions includes wideband RF detectors for the near vicinity, simple spectrum monitors for a distance range, where mobiles are detectable by their relative field strength compared to the band background and advanced W-CDMA/UMTS sniffers with protocol decoding, that can distinguish between base station and mobile transmissions.

 

[razvanel]

WCDMA sensors

can you give me an example of a simple device? or a site where i can look for one?

yes it's something along the lines of a wcdma sniffer, and that is a good point of comparing the field strength compared to band background.

near means a few centimeters...as near as possible, no minimum distance constraints.

i found only one such device that looks cheap and says it can do the job. what do you guys think?
https://www.alibaba.com/product-fre..._Detector_Portable_Mobile_Phone_Detector.html