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(Solved) unable to put 3d patch antenna on top of 3d substrate with ground plane
Posted Aug 13, 2014, 6:58 p.m. EDT Low-Frequency Electromagnetics, MEMS & Nanotechnology, RF & Microwave Engineering, MEMS & Piezoelectric Devices, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 4.3b 1 Reply
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A few weeks ago i posted a topic similar to this one where I couldnt find out how to simulate a 3D patch antenna "on top" of a 3D substrate having a different material than its substrate, along with a 3D ground plane (finite thickness) below the substrate. The model library tutorial simulated the 3D patch antenna "inside" of a substrate and I was wondering why I couldnt put the antenna on top of the substrate and also the tutorial used the same material for the antenna as the substrate. Well turns out you can do all of that the trick is that I was understanding how lumped ports actually worked. I kept on reading about them but missed that one small line written there in the manual. That lumped ports can only work if they are connecting "two metallic or PEC faces" ONLY. Cause you see it applies a potential difference between these two PEC or metallic faces and that is how a wave is applied to the patch antenna. If you observe the tutorial at www.comsol.com/model/microstrip-patch-antenna-11742
for "micropatch antenna" makes a 3D patch antenna inside of a substrate both having thickness of about 0.508mm. The bottom of both the patch and the substrate is PEC. Also only the top of the patch is PEC. The lumped port height is also 0.508mm so it connects the top of the patch (PEC) to the bottom of the substrate (PEC) which is also acting like a ground plane for the antenna. Also the substrate has 0-conductivity while PEC makes the conductivity of the patch and ground plane nearly infinite. So when we run this model it excites the antenna into transmitting radiation.
In view of the above you can put a 3D patch on top of a substrate apply to it a material (different to the substrate material) and also define a seperate ground material and domain. As long as you have a lumped port joining the top of the patch to the bottom of the ground plane and you apply ur excitation to that lumped port. I am attaching my model (without meshing) which contains the above described antenna and still resonates at the 1.6387GHz freq as of the patch inside substrate model in the library.
In case anyone is interested I hope this helps.
Thanks, do comment please since I am new to this as well and I need to learn more about this still.
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