aaron_do
|
Hi,
I believe they are talking about the degeneration inductor, Ls, in an inductive degeneration LNA. Ls is chosen to be equal to Rsource/ωT where Rsource is usually 50 ohm. I'm not sure why they say it is independent of biasing and device width for a short-channel device however.
For long-channel, ωT = μn(VGS-VTH)/L2 [Razavi, Design of Analog CMOS Integrated Circuits, ch2, pp. 40] so if anything, the choice of Ls should be independent of the bias current and device width for a long-channel device...unless i've misunderstood something...
cheers, Aaron
|