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Setting the bias point of a discrete MMIC

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neazoi

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According to this http://217.34.103.131/pages/pdfs/an60010.pdf it has to be driven by aconstant current source.
I am trying to make one of these super wideband discrete MMICs.
http://www.qrp.pops.net/images/2010/rf-workbench1/my-mmic.png
http://images.elektroda.net/11_1296043527.jpg

By reading at the pdf file, I believe instead of using the bias resistors, an active constant current source would be better?

Could you suggest a simple, 1 or 2 BJTs variable constant current source schematic, so I can sed the current of the discrete mmic?

How about this one? it seems nice!
http://www.seekic.com/blog/project_...ant_Current_Source__for_Ultrabright_LEDs.html
 
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pstuckey

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This attachment has a detailed description of how to implement an active bias circuit.
 

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neazoi

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This attachment has a detailed description of how to implement an active bias circuit.
Interesting, but it uses opamps.
What if I keep the voltage stable, would the current then be stable? I am confused by the term "device voltage" used on the mini circuits file. Is it the same as the PSU voltage or it is something internal to the MMIC?
 

tony_lth

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You also can make a constant current with LDO. There are many claasic circuits in web.
 
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    neazoi

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neazoi

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