gsm impedance antenna

Hi

I am using a GPRS/GPS module
I face a strange problem Suddenly the GPRS is not working and when I measure the impedance on the antenna connector I found it equals to 1.2 ohm, I m expecting to see 50 ohms
am I true?
dose that means that the LNA and PA has burnt out due to ESD?

Salam
Hossam Alzomor
www()i-g()org

How are you measuring the impedance?

I am using ohmmeter

Then you're not measuring the impedance - you're simple measuring the DC resistance of the output. For that, 1.2 ohms is not unreasonable.

hi

do you know exactly what should be the value to be measured by ohm meter on antenna output?

Hmmm! You are using the ohm-meter to measure the impedance!?
I was so stupid to pay S50.000 for a Network Analyzer when actually a S10 multi-meter would be fine.

Hi

as you can see the ohmmeter was not suitable for doing the JOB.
but I think network analyzer is so expensive also .
what about using RLC meter?

Salam
Hossam Alzomor

RLC meters make measurements at low frequencies. As vfone said, you _do_ need a VNA for measuring the impedance of an antenna at GSM freqs. Of course, you can use a SWR meter (cheaper solution) but in that case you will not not measure the input impedance but something related with.
Good luck

I feel you may be wasting a lot of your time trying to measure the radio's impedance. The module is either good or bad, trying to measure the impedence isn't doing you much good. If you use a different module with your SIM card, does it work? Is it only GPRS that doesn't function, or can you not connect to the network? I've destroyed a few modules myself, and its always been fairly easy to determine if its working or not.