Why two stage amplifier?

[mic5]

I have read an article in which, two stage RF amplifier is used which have gain of 11dB and 31dB respectively.

My question is why these two stage of amplifiers needed? Why can't we use 42dB amplifier?

What are the benefits in terms of cascaded amplifiers here?

 

[ericgibbs]

I have read an article in which, two stage RF amplifier is used which have gain of 11dB and 31dB respectively.

My question is why these two stage of amplifiers needed? Why can't we use 42dB amplifier?

What are the benefits in terms of cascaded amplifiers here?

Consider bandwidth, what is the bandwidth of the RF amplifier you quote.???

 

[4pyros]

One may be a voltage amp and the other a currant amp.

 

[crutschow]

You may not be able to build one stage with both the desired gain and bandwidth.

 

[KeepItSimpleStupid]

Remember too, that multiple stages multiply the gains and not add.

 

[crutschow]

Remember too, that multiple stages multiply the gains and not add.

But if the gains are expressed in dB they add. That's one advantage of expressing gain in decibels.