Learning Forum

[pengzheng97]

Hi, I wonder How to get the amplitude and phase of a point in FDTD or MODE, not transmission, what monitor should be used for the information

[Niki Papachristou]

Hi Pengzheng,

Thank you for contacting us,

In FTDT you could introduce a mode expansion monitor (Using and understanding Mode Expansion Monitors) and ports (Ports (FDTD) - Simulation Object) at the positions of your interest for both the amplitude and the phase. From this point you can extract the phase, which is connected with S-parameters, as well as with field component and mode. So taking advantage of S-parameters of FTDT you can use angle script command ( angle - Script command) to get the phase. The same case with S-parameters applies on EME solver by using ports.
 
A simple example how you can use the S-parameters is quoted below:
SS=getresult("FDTD::ports::port 2","S");
S21=SS.S;
Phase=angle(S21);
?phase*180/pi;   #in deg
 
You could also get the phase by using a frequency-domain monitor (Frequency-domain Profile and Power monitor - Simulation object) of an individual E component. However, special care should be taken as getting the phase from a frequency monitor it depends on the position on the monitor.
 
I hope that was helpful, let me know if I can be of further assistance.

Kind Regards,

Niki