What's the difference between S and Active S in HFSS??

[juzhen]

hfss active s-parameters

Hello,everyone!
Now I'm doing some research about phased array antenna with HFSS. When I see the report, the S Parameter and Active S Parameter (VSWR and Active VSWR)puzzle so much ! which one I should pay attention to ??

Appreciate for your answer!!

 

[ermai]

active s is the reflection coefficient of one port when another port is excited...

for example, a 2 port system ,the total reflect wave at port 1 is S11*V1+S12*V2
the total reflection coefficient is total reflect wave at port 1 over total incident wave at port 1,then reflect coefficient is (S11*V1+S12*V2)/V1,which is the active S(1:1)

 

[kae_jolie]

active s is the reflection coefficient of one port when another port is excited...

for example, a 2 port system ,the total reflect wave at port 1 is S11*V1+S12*V2
the total reflection coefficient is total reflect wave at port 1 over total incident wave at port 1,then reflect coefficient is (S11*V1+S12*V2)/V1,which is the active S(1:1)

ok. you are the closest thread to what I am trying to do. I understand how Active S is calculated, but how is it used in HFSS? I am trying to match a 5-element dipole array to achieve max power transmission using Active Z parameter values. I have all 5 ports excited, run simulation, read the re and im values for Active Z for each port, then enter them as the input impedance for each lumped port, then re-run simulation. Still not all incident power get accepted, which means more power is reflected.
Am I doing something wrong? perhaps not using Active Z parameters correctly? I tried to zero the excitation power for all ports except one and get the Active Z value just for the excited port, then move to next port and do same thing, but that didn't improve the results.

Thank you.