Measuring a differential LNA's impedance w single ended VNA

[dz99]

Hi there!

Any suggestions around this topic? In my memories deep down somewhere there are flashes of this solution...

I think I need to connect to SMA connectors (common grounded) to each of the two input. Then S21, S12 measuring, and then what? What would be the way? Mathematical post processing of the S parameters? Ideas? Textbooks, books are welcome! n

Thanks!

Cheers,
Zoltan

 

[kspalla]

You can use balun at both input and output. Share the schematic, data sheets if any.

 

[Mazz]

Re: Measuring a differential LNA's impedance w single ended

Read the attached paper and you'll have the solution.
Mazz