Discussion Forum

From last 6 months, I have been trying to learn COMSOL Multiphysics. I couldn’t find anyone to discuss my doubts while doing the tutorials for Plasmonic wire grating and FSS , split ring resonator. I finally found this blog where periodic structure is discussed as my work is also on periodic structures. Writing my questions here hoping that would be answered by you or anyone who will read this.

While going through the FSS/Split ring resonator I have following doubts:

1) the (1) emw.k0*sin(theta)*cos(phi) (2) emw.k0*sin(theta)*sin(phi) (3) emw.k0*cos(phi) are put in variables. Can we write them in parameters? And I think these components determine the direction of incident of light. And also writing them in variables means this is the wave which we incident on the structure, right?

2)Difference between domain backed and PEC slit type. What actually their functions are and how would they affect the simulation?

3)Port orientation is been taken as reverse for both ports 1 and 2. Why? And the directions of the arrow of the port is same whether I click it for forward or reverse. What does it make difference?

4) While defining the properties of port, input quantity is given as magnetic field. Why it is magnetic field, can’t we put electric field as a input quantity ? And also exp(-i*k_x*x)*exp(-i*k_y*y) j A/m is given for the mode, it means wave is traveling in XY plane K has both the component kx and ky and the direction of magnetic field is along y direction. but magnetic field should be perpendicular to direction of propagation.
4) again if wave is propagating in XY plane than how the propagation constant beta = abs(k_z)?
5) Since both plasmonic wire and FSS are periodic structure then why port periodicity is considered in former one not in later one?

I am lost. Please help me out.

Thanks
Kalpana