[SOLVED] current reuse technique

[gold]

Hai to all ,
what is the use of current reuse technique in LNA design? How can we know the reduced power consumption by using this technique in ADS tool?
I mean, how can we calculate this reduced power consumption by this technique?

what is the difference, when we use current reuse technique in LNA design ?

plz reply as soon as possible . thank you

 

[erikl]

what is the use of current reuse technique in LNA design?

Less power consumption than an LNA with 2 separate gain stages.
Current reuse technique is nothing else than a cascode (dual) stage. Same bias current for both gain stages.

How can we know the reduced power consumption by using this technique in ADS tool?
I mean, how can we calculate this reduced power consumption by this technique?

Compare the power consumption of a current reuse LNA with that of an LNA with 2 separate gain stages. Usually less than 50%.

what is the difference, when we use current reuse technique in LNA design ?

Lower power consumption, lower gain, lower linearity. You trade less linearity for less power consumption.

 

[gold]

Thank you for your reply Sir.

I have a doubt in following structure.
Fig 1: **broken link removed**

Fig 2: **broken link removed**
Both LNA structures has the same DC path. can we say the first structure is a current reuse structure?
why should we call the fig 2 as a current reuse structure?

 

[erikl]

Can't read your attachments, sorry.

 

[gold]

what is the diff b/w these 2 structures? Both LNA structures has the same DC path. can we say the first structure is a current reuse structure?
why should we call the fig 2 as a current reuse structure?

 

[erikl]

The 1^st one is a CS-CS cascode stage, the 2^nd one a CS-CG cascode stage. Both use the so-called current reuse structure, which is the same as a (non-folded) cascode structure. A single current for 2 gain stages. Or you could say: The bias current of the 1^st gain stage is "reused" for the 2^nd gain stage.

 

[gold]

Thank you @erikl