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Designing X-Band LNA in ADS

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fizi

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i am designing lna with ADS,i have problems since i cann't get tor NFmin the company has mentioned.nither the Sopt.
also i have some problems with matching network . i need a tutorial.any suggestion?
thanks
 

dingjingfeng

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X-Band LNA

There is a lot of LNA book in this forum
 

RFCMOS

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Re: X-Band LNA

Hello,

Take a look to the following link:
www.rfic.co.uk
You should find some tutorials related to LNA.
Hope this helps.

regards.
 

khouly

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X-Band LNA

if the company u use thier transistor, didn't mention the NFmin , and the Sopt , u need to measure them in ur company

khouly
 

springf2000

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X-Band LNA

there are many book,for example "the microwave transistor amplifier design"
 

RF-OM

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Re: X-Band LNA

If you need to design LNA with optimal noise matching (with gamma-optimal) you need to know noise S-parameters for chosen active device. It can be found at the end of S-parameter file. You have to know such information in order to do optimal noise matching.

There are a few words of precaution. Optimal noise matching sometimes can improve the noise figure. This is the true. But with today’s well designed active RF devices it is often not necessary to do. You need to check what mismatch loss you will get with optimal matching versus conjugated matching. Often this loss is bigger than noise figure improvement from optimal matching and therefore such matching is meaningless. And is wider your bandwidth as harder to get optimal noise matching, and as more negative effects from implementation loss.

Next question is about RF system design: is it really shows that such a high noise figure (that requires optimal matching) is necessary? Often external problems (such as real noise picture) and system linearity are limiting actual noise performance so hard that there is no sense to struggle with optimal noise matching.

Best regards
 

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