LNA, NF, S parameters in HSpice
时间：04-08
整理：3721RD
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Guys I have this problem and I need opinions.
In my uni I have only the transistor models that can be used in Hspice. I have no transistor models to use in ADS.
That is why I can only use Hspice to design an LNA and check its parameters. But I am not sure about some stuff:
1) is it necessary to simulate noise at the input port of my LNA? The actual RF circuit will take an input full of different kinds of noise. So I kind of feel it is far from the actual case if my input was crystal clear.
2) How to add noise to the circuit itself? I mean when I use .NOISE command, what kind of noise it adds, and on what basis? How do I change the amount of noise? What if I only want noise on specific components?
3) How to measure NF in simulation? What command should I use?
4) How to measure S parameters? What command should I use?
5) Is NF = S12 always?
Thank you.
In my uni I have only the transistor models that can be used in Hspice. I have no transistor models to use in ADS.
That is why I can only use Hspice to design an LNA and check its parameters. But I am not sure about some stuff:
1) is it necessary to simulate noise at the input port of my LNA? The actual RF circuit will take an input full of different kinds of noise. So I kind of feel it is far from the actual case if my input was crystal clear.
2) How to add noise to the circuit itself? I mean when I use .NOISE command, what kind of noise it adds, and on what basis? How do I change the amount of noise? What if I only want noise on specific components?
3) How to measure NF in simulation? What command should I use?
4) How to measure S parameters? What command should I use?
5) Is NF = S12 always?
Thank you.
See the followings.
http://www.designers-guide.org/Forum...1171334993/1#1
http://edocs.soco.agilent.com/displa...CE+and+Spectre
https://www.edaboard.com/viewtopic.p...016&highlight=