Negative waveguide loss

- September 18, 2022 at 7:26 pm
  
  能勢武尊
  Subscriber
  
  Bending loss is calculated.
  The result is negative loss as shown in the following picture.
  Why is this?
  Also, when the mesh is eliminated, the loss becomes positive. Why is this?
- September 19, 2022 at 3:24 pm
  
  Guilin Sun
  Ansys Employee
  
  This is numerical error due to discretization. You may increase the simulation span along the bending direction. You can also correct this negative loss by allowing mode propagating in the negative direction, eg, real(neff) is negative. In most cases it is ok to have the fake "gain" as you know it is due to error.
- September 20, 2022 at 5:48 pm
  
  Guilin Sun
  Ansys Employee
  
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