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Measurements >> RF Measurements >> Balu-LNA design
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Message started by prakash@191 on Oct 18^th, 2011, 1:54am

Title: Balu-LNA design
Post by prakash@191 on Oct 18^th, 2011, 1:54am

I have designed balun-LNA using parallel combination of CS and CG stage. My circuit has differential output and single ended input. I matched the input for 50ohms since it is single ended. But my doubt is how to match the differential output for 100ohms.
For output impedance matching, i have separately matched the output for 50ohms assuming virtual ground.(for both outputs of CS and CG buffer stages). After matching i lifted the virtual ground and the output capacitors will come in series. I replaced them with single capacitor ( series combination). I haved used capacitors for matching purpose at the output of buffer stages.

With this setup, i measured S22 by keeping port in between the terminals.
I want to know whether my way of thinking is correct?

Any help would be appreciated