Reply To: Port Reference Impedance Definition in SiWave

[Mrinmoy Bharadwaj]

Hello Reza,
Thanks for reaching out. 
The reference impedace of the port here refers to the impedance of the source at which the energy is fed into the system. This reference impedance comes from the basic definition of scattering parameters at a port. It is desirable that this impedance is kept equal to the input impedance of the system to ensure maximum power transfer between source to the system. Usually for transmission lines a 50Ohm value is chosen as most transmission lines are designed for 50 Ohms but there are exceptions as well, where other values might also be used. You can find more details in the S-parameter technical notes in the help document of SIwave. Hope this helps in your understanding.