design a 90 degree hybrid coupler 2-8GHZ

Question

I designed a 90 degree hybrid coupler in hfss, in 5~6 GHZ. S₁₁ & phase difference are okay, but S₂₁ & S₃₁ don't match.

What change should I make in the form to improve matching between S₂₁ & S₃₁?

hm, can you tell us which port is which? – Marcus Müller Jan 30 '19 at 19:02 — Marcus Müller, Jan 30 '19 at 19:02
this is when you would use the optimizer – johnnymopo Feb 03 '19 at 19:55 — johnnymopo, Feb 03 '19 at 19:55

score 2 · Answer 1 · answered Jan 30 '19 at 19:09

Generally, I can only assume that these mismatches stem from the effects of asymmetry. Note that your <4.5 dB mismatch doesn't look all that bad!

you could ever so slightly adjust the angle of your feeds and see where it takes you, but you'll probably lose a bit of your nice S11 that way.

However, I have no clue how well you can achieve such a wideband match as you did with that.

1 Answers1