Problem with designing a SIW slot antenna on Alumina

Hi all,

I'm trying to design a Substrate Integrated Waveguide (SIW) slot antenna on Alumina, and I can't for the life of me get it to resonate. I followed all the design methodology in literature and in text books. Curiously, I designed another version on a lower dielectric constant substrate, and it worked like a charm.

Anyone have any leads to why it's not working on Alumina?

-Sam

It can be a problem of dimensions of the waveguide structure!

Here some ideas:
- add some stub walls in the waveguide
- add metallic apertures around slots and optimize the thickness of the apertures
- add horn section to change the waveguide section
- try to make the slots very cloth to create a resonance phenomena

Upload your design, so we can examine it.