Ansys Learning Forum Forums Discuss Simulation Electronics Graph Difference Phases of Septum Reply To: Graph Difference Phases of Septum

Irina G.
Ansys Employee

Hello,

as I understand, your design of OMT has 2 waveports on one side (green and red, one mode each) and yellow wavport with 2 alined (degenerate) modes on the other side. If you want to work with fiedls, it's better to add some kind of horn instead of yellow port and report LH and RH CP strength in Far Field wnen one of ports (green or red) On. Usually Axial ratio value is also important.   

When keeping 3 ports, one need to create output variables as proxy to LH and RH circular polarized fields. For ideal circular polarization starting from green port, the conditions should be as follow:

mag(S(green, yellow1))=mag(S(green, yellow2)) and  cang_deg(S(green, yellow1)) - cang_deg(S(green, yellow2)) = +/- 90deg. I would start with optimizing based on phase difference of S-parameters in the desired frequency band.

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