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low noise amplifier with active inductors (Read 1124 times)
anonymus
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low noise amplifier with active inductors
Jan 17th, 2018, 10:20pm
 
Hello all,

I'm designing an Low noise amplifier with active inductor for 2.4 GHz with 180nm tech, i want to replace the inductors present in the lna designed  earlier with active inductors.
1)what is the maximum inductance value that could be achieved with active inductors?
2)what could be the better choice of active inductor that is connected to VDD having a value of 5.4 nH and an inductor connected between 2 mosfets having a value of 7.57 nH?

Here i attached the partial circuit where i want to repalce the inductors


Thank you
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lna_query.png
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Jacki
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Re: low noise amplifier with active inductors
Reply #1 - Mar 26th, 2018, 5:43am
 
I haven't worked with active inductors for some years, but do you think it is a good idea to use the active inductor in the LNA? Because it is very noisy. About the absolute inductance value I think you can do either a simple calculation or use a simulator to estimate it. Be careful about the Q. If I design this LNA, I would prefer to replace the inductor between the cascode stage to extend the bandwidth, and hope the noise contribution is not too high. I will not consider to use the active inductor at the load.
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kumar.g
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Re: low noise amplifier with active inductors
Reply #2 - Apr 23rd, 2018, 5:19am
 
Like Jacki has mentioned , the active inductors are too noisy to be used in an LNA. Also replacing both the inductor with an active inductor will lead to 4 stacked MOSFETS (in total)) and this will lead to voltage headroom problems.
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