Setting the bias point of a discrete MMIC

[neazoi]

According to this **broken link removed** it has to be driven by aconstant current source.
I am trying to make one of these super wideband discrete MMICs.
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http://obrazki.elektroda.pl/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

 

[pstuckey]

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

 

[neazoi]

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]

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

 

[neazoi]

What is an LDO?

 

[tony_lth]

LDO: Low drop output.

 

[kayaoo]

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http://www.vidisonic.com/2008/07/10/current-limiting-circuit/

 

[neazoi]

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This is exactly what I need.
I am thinking of using 2n2222 transistors to drive the two cascaded amplifiers of this one **broken link removed** (one pair for each cascaded amp)
What would you recommend as a starting point for the resistor values for each cascaded amplifier?