How to measure receivers sensitivity

Hi
How to measure the sensitivity of RF devices ? What the equipments I must have to complete this job. Thanks in advance.

Hi,

you basically need an RF generator able to generate a digital data and modulate it with a carrier. Next, you need to find a way to compare the data sent into your receiver with the data demodulated by your receiver. Sensitivity is the power level sent into your receiver for a chosen number of wrong received bits.

Hope this will help

Hi Ghost Tweaker,

If I don't have a signal generator, what can i do ? Can I use network analyzer plus attenuator to instead signal generator ?

No but you could use your transmitter and measure the received signal power with a spectrum analyser at the input of the receiver. Forget about about the network analyser, you need modulated data at a fix frequency which is not at all what's generated by network analyser.

See ya

All the receivers use some basis signal (sinusoid usually) for confirming that the signal is acquired. So if you have single tone generator for the center frequency it will be all right.

First ensure that the bandwidth is correct. You can do this by providing a large noise power at the input. Just connect an LNA to the input and observe the spectrum.

Now set the input signal strength to the minimum value you require. Adjust the RBW and VBW on the spectrum analyzer to mimic your Coherent and Non Coherent integration Times as closely as possible. If you can observe the IF clearly you are through.

You absolutely need an RF generator, because trying with the transmitter you will have so many leakings that the measurement will be not true.
I remember one time a guy called me from a different country and told me that the receiver I designed had a - 140 dBm sensitivity.
Knowing the project I can expect about 1 - 1,5 db Spread in the characteristics ( with a normal sensitivity of - 108 dBm), but not - 140 dBm.
He swear that the measurement was done properly, but after some explanations he told me that he was without a RF generator and he used the transmitter ( a 2 W transmitter ) as generator, with some attenuators.
But the trouble was that the transmitter and the receiver were about 20 centimeters one to the other.
Explained him the mistake he found ( lean ) an Rf generator and he found the sensitivity be - 70 dBm due to overload ( and failure ) on the first preamplifier after the preselector (someone connected directly the transmitter to the receiver ! ).

Mandi

Try with noise generator

normally generator will be ok if you have no other requirement