Discussion Forum

All,

I'm trying to model a 2D parallel-plate waveguide that has coupling structures attached to the parallel-plate (very similar to conical horn antennae). I want to simulate the waveguide using THz frequencies. In my experiment, the incoming THz pulse is TEM with the electric field polarization vertical (between the plates). The waveguide also operates in TEM, or the TM0 mode. I need to compute the coupling of the waveguide, assuming the THz beam (bandwidth 0 - 5 THz) enters the waveguide on the left and exits on the right.

I've tried building my model 2 ways:

1) Building the waveguide structure, then leaving only the negative space between the plates and trying to place the Port 1 directly on the left of the structure and Port 2 on the right

2) Enclosing the waveguide structure with a circle of air, combining the encapsulating air space with the negative space between the waveguide plates, and leaving the plates present while setting their material definition to be copper

I am using the Electromagnetic Waves physics for this simulation. In both cases, I am unable to compute anything for the final model, getting an error everytime.

I am rather new at this. I've tried looking through models on both the Model Exchange and those created by COMSOL and I haven't determined the source of the error, although I'm sure it's because I've set a definition wrong somewhere, likely in the physics portion of the program. I'd really appreciate any assistance anyone has to offer!

NOTE: I could not attach the second file with the encapsulating circle. The file size became too large, even when I deleted the mesh. But for reference, I placed a circle with a radius of 0.1 m at the (x,y) coordinates (0.015,0)m. I then used the Union function to combine the circle with the negative space left over from the Difference function and applied the Air material to it. I also adjusted the Difference function so that the plates of the PPWG were visible again, and then I applied the Copper material to them.