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LNA gain and input matching (Read 17182 times)
yixiusky
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Re: LNA gain and input matching
Reply #15 - Oct 02nd, 2010, 11:59pm
 
pancho_hideboo wrote on Oct 2nd, 2010, 10:46pm:
As another possibility, unless impedance of Vdd is enough low, extraordinal oscillation could occur between Vdd and drain of M2.
Then it breaks drain of M2.

Try to place 10pF, 100pF, 1000pF and 100kohm between Vdd and Gnd.


I have  question

You mean place all 10pF, 100pF, 1000pF and 100kohm in parralel? or place just one by one, and test?

My frequency is wideband, from 1.8~2.7Ghz.

From VDD to ground, when I place the capacitor, which value should I choose?
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pancho_hideboo
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Re: LNA gain and input matching
Reply #16 - Oct 3rd, 2010, 2:13am
 
yixiusky wrote on Oct 2nd, 2010, 11:59pm:
You mean place all 10pF, 100pF, 1000pF and 100kohm in parralel?
Yes.

10pF must be placed in most near of Vdd.
100pF is next. And 1000pF is next to 100pF.
100kohm is near of 1000pF.

BTW, what value do you apply as stimulus power in Network Analyzer ?
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« Last Edit: Oct 3rd, 2010, 3:39am by pancho_hideboo »  
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snaildr
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Re: LNA gain and input matching
Reply #17 - May 7th, 2011, 7:52pm
 
Why do you use resistive feedback and also inductive degeneration? I though the point of using resistive feedback and thus making the NF a bit worse is to go without any inductor and save a ton of area, right?
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