Hi,
We have simulated a ceramic BLE antenna in two scenarios: with and without wood nearby. In the simulation, we observed that the presence of wood causes a shift in the S-parameter and reduces the antenna efficiency by about 30%. Without wood, the efficiency is around 70%.
However, in our real lab tests, the S-parameter only shifts when the PCB is in direct contact with the wood. If there is any separation, the effect is minimal or nonexistent.
Is it normal to see such a discrepancy between simulation and empirical results? Does it make sense that wood has such a strong impact in simulation but only affects performance in practice when there's direct contact? What could be causing this difference?
-Cases in simulation:
[1] Antenna + Full Wood Block
[2] Antenna + Wood with Cutout
[3] Wood with Cutout + Raised PCB (2cm)
[4] Bigger bounding box
