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All things pertaining to wireless and RF links
By zuk
#160878
Hello,

I am trying to make a basic GSM detector that I could use in a small room. Basically it would turn a LED on everytime a cellphone in that room received\made a call\sms.

I am thinking in using this antenna and a TI RF power detector like the LMH2121.

Does anyone ever used either component? Or, would this development board allow me to do what I wanted (I would need to connect it to a uC)?


Thank you!
By stevech
#160987
too much varied RF in room.
For GSM, you'd need a bandpass filter ($$$).

Such a device is available commercially, but quite expensive.
User avatar
By languer
#161222
Seems like an interesting project. What GSM frequencies are you after? You will likely need to discriminate against the frequencies you don't want. Which means some sort of bandpass filter (like stevech mentioned). But I don't necessarily think it has to be a very expensive filter. Anyways, if you can figure out the frequency band you want, an LNA coupled with either your own (built) filter or a purchased one, and the antenna you suggested, and detector you suggested could work. The main issue I think is that nearby cell phones operating in the same GSM network are extremely likely to trigger this (which may be what stevech was referring to).