The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> RF Design >> LNA stability problem at low frequencies
https://designers-guide.org/forum/YaBB.pl?num=1208223824

Message started by skywlj on Apr 14th, 2008, 6:43pm

Title: LNA stability problem at low frequencies
Post by skywlj on Apr 14th, 2008, 6:43pm

I'm designing a LNA at 2.4GHz but finally the low frequency stability becomes a problem. Any good solution for that? If resistors are added to stabilize the circuit, the noise figure and power gain will be much worse.

Title: Re: LNA stability problem at low frequencies
Post by aaron_do on Apr 14th, 2008, 11:21pm

Hi,

i don't think you gave enough details. Perhaps a schematic would be helpful, or at least a description of the circuit...

Aaron

Title: Re: LNA stability problem at low frequencies
Post by skywlj on Apr 15th, 2008, 2:16pm

The source inductor degenerated LNA with cascoded structure is used. The output for Kf and Bf at low frequency is very large 10^66 at very low frequency. The Kf and Bf from 100 KHz to 200 KHz is attached. It looks very funny. For higher frequency ( from 1MHz to 10GHz), the reported Kf and Bf are normal and show the LNA is stable. Does this come from the computing error?

The Designer's Guide Community Forum » Powered by YaBB 2.2.2!
YaBB © 2000-2008. All Rights Reserved.