[ibis-macro] touchstone file in BIRD119

  • From: <fangyi_rao@xxxxxxxxxxx>
  • To: <ibis-macro@xxxxxxxxxxxxx>
  • Date: Tue, 26 Oct 2010 22:59:36 -0600

The reference impedance specified in touchstone file is the termination 
condition under which S-parameters are measured. It doesn't mean the 
S-parameter block has to be terminated by the exact same impedance in the 
actual circuit. It's perfectly fine to connect a S-parameter block measured at 
50Ohm to a 75Ohm termination or any other network. Different terminations lead 
to different reflections and different responses. So in my opinion the 
definition of Rx circuit with s4p touchstone in BIRD119 is incomplete. It's 
like you have a capacitor in the circuit but you don't know how one of its two 
terminals is connected.

Regards,
Fangyi

Other related posts:

  • » [ibis-macro] touchstone file in BIRD119 - fangyi_rao