Quadrature Hybrid Coupler for Antenna

[huytergan]

Hello everyone,

I wanna design a quadrature hybrid coupler for antenna. There're couple of videos on youtube that explain and design. I firstly wanna design it, see the result and then apply to a patch antenna. However, the videos apply electric-field boundaries in all directions, but antenna is analyzed far-field (open-add space) What's the true here, should I analyze the coupler as open-add space too? In this case I don't get what I want. But, I get in the case of E-field applied in all directions. My mind is confused... (I'm using CST btw)

Thanks in advance
Regards

 

[vfone]

Any type of coupler should NOT radiate EM waves.
A printed coupler (as any other printed or microstrip component) would radiate to some extent, do to the nature of the EM fields surrounding the lines.
To get low insertion loss, the radiation of those fields should be kept as low as possible, which is in opposite when is about a printed antenna, which should radiate the EM fields as much as possible.
Simulating a printed coupler with a 2D simulator should be enough, but simulating in 3D or far-field (together with the antenna) is not wrong either.