Why 50Ohm balun is not 50Ohm？

Hi，everyone!
I am designing a RF block.

But when doing match, i get in trouble.

I find a 50 Ohm balun dodoes not show 50 Ohm charactor.

Detail content is in the attached file.


Thank you for everyone' s help~

Hi

Balun is a two port circuit, one port is unbalanced port, other port is balanced port (although this looks like two-port output, it is indeed one port - balanced). On differential (balanced) port, 1-1 balun should see 50 Ohms.

In your case you have two single ended ports in place of a differential port. In that case, port impedance should be 25 Ohms.

flyhigh

Thank you. I will try your suggestion.