What kind of RF noise to look for at 1.7 GHz?

[Hi-Tone]

Hi guys.

Does anyone know what kind of RF noise to look for at 1.7 GHz?

Im looking at Noise Figure and all i can use google for is Thermal noise. Isnt their any kind of other RF noise out there or is this the only kind of noise that the Agilent NF instruments measure?

Thank you,
Steve

 

[Milad-D]

Re: RF noise in 1.7 GHz.

Except thermal noise, you might implicitely measure the external interferer as a noise and you might get higher noise due to this.
if this is the case, then you may need to measure the noise figure in faraday cage for example.

FYI: there is utms-1 band from 1710 till 1755 Mhz.

 

[Hi-Tone]

Re: RF noise in 1.7 GHz.

Thank for the response.
So there is no other real noise such as shot noise in that frequency range?
Btw. do you know what the noise floor level is at, at 1.7 GHz.

and yes, im making an LNA for UMTS 1710 - 1755.

 

[Milad-D]

Re: RF noise in 1.7 GHz.

It depends on what type of transistor you use. If you use mosfet, then the thermal noise is the dominant case. But if you use BJT transistor, then you have shot noise plus the thermal noise contribution of base resistance.

The noise floor is ~ -174dBm+NF(dB).