13.56MHz RFID loop antenna simulation

How to use openEMS. Discussion on examples, tutorials etc

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13.56MHz RFID loop antenna simulation

Post by SizzlingCPU » Tue 18 Aug 2020, 10:51


I am trying to simulate a 13.56 MHz RFID loop antenna. The antenna has some resonance and matching components. I think the structure is shown correctly (AppCSXCAD output from openEMS). I used AddWire and it does seem to have some discontinuities, not sure if these are real or not ? I read that the mesh selection is important with openEMS - I left this to DetectEdges, does this need further refinement ?

The fundamental problem is that the RFSIM99 simulation S11 return loss does not match the openEMS derived S11 return loss. There should be good antenna absorption with minimal reflection at 13.56 MHz. My openEMS simulation does not show the same return loss and hence I don't have much confidence in its validity.

Fundamentally I'd like to explore the spatial H-field of the antenna at resonance. I hope that it is possible with openEMS. It does seem like a good tool although my experience with FDTD-based simulations is limited; I'd like to use this model to develop my experience.

I include my m-file. Since I have reached a brick wall, any pointers would be appreciated.

Single Loop Antenna.png
Single Loop Antenna.png (160.78 KiB) Viewed 3915 times
S11 Return Loss (openEMS).png
S11 Return Loss (openEMS).png (38.76 KiB) Viewed 3915 times
S11 Return Loss (RFSIM).png
S11 Return Loss (RFSIM).png (49.71 KiB) Viewed 3915 times

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