How come differential cascode structures affect on PA characteristics?
I was reading the paper A WLAN RF CMOS PA with Adaptative Power Cells by Taehwan Joo, Bonhoon Koo and Song-cheol Hong, and in the design topic of such paper, the authors stated that:
1) Differential structures alleviate bond wire effects and
2) To achieve sufficient gain in differential strucutures, virtual grounds in the CG are essential.
How come those two points happens in a mmW RFIC PA design? Could anyone explain me those two sentences?
Many thanks.
Hi. In which frequency is this paper? what do you mean by mmW? 5 GHz or 100 GHz? It is important to know.
I have read many of this professors PA papers and I can say with comfort that they do not explain in their papers the procedure and they usually infer strange conclusions: Simply put, they have a circuit with a good performance and then they explain general things and infer that the performance is due to these general remarks. All PA circuits in the world are differential and cascode (common gate).
Hi, thank you for your answer!
Operating frequency is 2.4 GHz. Maybe they were saying that with differential architectures less current flows through the bond wires, thus, increasing power gain?
As for the virtual grounds, I still got no idea on how to start understanding the statement of the authors...
Hi. As I said above, do not rely too much on their info. I have wasted long times understand or reproduce their designs. In my opinion, they have this performance and they do not have a good explanation.