[SOLVED] CST MWS problem: periodic boundary + waveguide port

[ylzhang508]

Hi all,

I m trying to simulate a metallic periodic structure with the Transient solver, the structure composed periodic arrays in x-y plane and the wave incident from z-axis, I use periodic boundary conditions in both x and y direction, waveguide ports for top and bottom sides. When i run the model ,the following warning arises: Waveguide port 1 touches periodic boundary! ......

So, How can i set boundary conditions in x-y plane, need i use PEC + PMC instead? and, can i set waveguide ports inside the box?

Any suggestions are welcome!

Tks in advance.

 

[Jamesanton]

Hai, in x axis u put magnetic and in y axis u put electric and in z axiz open

then one port in the top then u can measure the reflection .

 

[ylzhang508]

Hai, in x axis u put magnetic and in y axis u put electric and in z axiz open

then one port in the top then u can measure the reflection .

Thanks u, James.

I wonder if you mean i should use PEC in x axis, PMC in y axis and set open and waveguide ports for up/bottom sides. I have tried the settings and it worked. But i don't know if it is right for unit cell without central symmetry? And how can i combine periodic boundary with waveguide ports?

 

[kaandee]

I also had same problem. but i have set the all boundary as open add space. then i didn't get any such problem. but it will increase no of mesh cells.

 

[ylzhang508]

I also had same problem. but i have set the all boundary as open add space. then i didn't get any such problem. but it will increase no of mesh cells.

dear kaandee,

Thanks very much

When do simulations with transient solver, We can't use periodic boundary directly. I have used PEC+PMC for x/y sides and open for z sides. Physically, PEC+PMC can serve as periodic boundary. You can use cell unit in frequency simulations, but frequency solver is slower than transient solver very much.

Zhang

 

[maciasas]

PMC and PEC does not give the same result every time, I have the same problem because I want to use periodic boundaries in cst (in hfss it works very good but slower)

 

[budder8818]

Hai, in x axis u put magnetic and in y axis u put electric and in z axiz open

then one port in the top then u can measure the reflection .

Does this simulate an array of periodic cells? What is the point of having the periodic boundary condition then if your suppost to use the magnetic in x and y electric?