snr calculation
Hi,
Try to use A/pp/CAD, you can find it at A/gi/lent Web site,
it's free.
Generally speeaking, the formula for the input noise figure of cascaded 4-poles is :
F=F1+(F2-1)/G1 + (F3-1)/(G1.G2)+...;
where:
Fn is the noise figure of the n-th stage,
Gn is the power gain of the n-th stage.
To calculate the cascaded stages noise figure you must know individual noise factors and power gain of tha stages. Noise factors are usually given in a bandwidth of 1Hz.
After this it's easy to convert the result to output power or voltage, taking into account the bandwith of interest.
Take into account also the frequency - the density of noice, generated for example by a bipolar transistor, is higher at very low frequency, because of the recombination,
I hope, above few words are usefull.
Best of luck,
STO