Adding phase shift (increase ray path length) for propagation results

Aurelien Surier

Dear community,

I have a custom SBR workflow in which I compute the electrical field in two simulations : (1) for a real feed (2) for an equivalent feed excited by the real feed.

For final results, I need to account for the path length from the real feed to the equivalent feed, corresponding to an equivalent phase shift (Phii in eq 45).

Can I do it directly in Winprop or I need to save the rays data file so I can add this path length in the path 'duration' or ray 'shift' columns ?

I have tried to compute the electrical field strength Etot from a simple model to check for the second solution, however I am unable to get same results calculated by ProMan software, according to help document [1], where I use the 'delay of path' field in ns to compute its length to get Phii, and the 'field strength' field as Effi as defined in eq. 45 from the ray data file [2].

[1] https://2021.help.altair.com/2021.1.2/winprop/pdf/Altair_WinProp_User_Guide.pdf, section 5.2 (superposition of rays)

[2] https://2021.help.altair.com/2021.2/winprop/topics/winprop/user_guide/proman/results/proman_results_type_ray_data.htm

 

Thank you,

rays-superposition.PNG

Zeina

Hi Aurelien,

If I understand correctly, you need to account for the position difference between the real feed and the equivalent feed. This implies that your equivalent feed is not effectively "equivalent" at the coordinate you are defining it, correct?

Note that a simple addition of a phase shift to your results might not be the enough to account for that ray path difference in practice. The SBR algorithm performs ray computation based on the number of ray interactions set in the project parameters. This implies that a small change in transmitter position can change the computed rays for a given receiver position, resulting in a different list of rays.

If you need more assistance, please share your project (File -> Export -> Export Project as Zip Archive).

Best,

Zeina