Ken Kundert wrote on Sep 23rd, 2015, 10:39pm:1. you are correct, but the cubic terms will be small and are considered negligible compared to the linear term.
2. I don't understand your question. You went through the mathematics to get the distribution, and then ask why. The why is explained by the mathematics.
-Ken
Thanks. Based on the former 2 questions:
1. If we can skip the the cubic and squared items, it means α,β<<1. Based on this premise, we can eliminate α,β and get the final formula which shows indepedence between iIP3 and α,β. Conversely, if α,β>1, α,β cannot be eliminated in the final formula so it means iIP3 has some relation with α,β.
However I know my conclusion above should be wrong because iIP3 is the non-linearity parameter of circuit and it should be only decided by the circuit itself. Anyway I don't know in which derivation part I make a mistake?
2. I know how to get the mathematics. But I don't know what' the reason to get the conclusion(50%,25%,25%) based on these mathematics.
Sorry for my long questions. Thanks a lot!