4.3 Creating ABC MUR Walls

Before we mesh the structure it is required to introduce absorbing boundary conditions along upper and lower substrate edges and at the top of the structure. In this case we need to use single absorbing walls instead of absorbing box. For the purpose of drawing the absorbing wall we choose MUR Wall option from the ABC button in the Model tab. Firstly we introduce two absorbing walls along Y axis, at position Y1=0 with PLUS activity and at Y2= 32.512 mm with MINUS activity.

Create MUR Wall dialogue for absorbing wall at position Y1=0 (a) and Y2=32.512 (b).

The last absorbing wall should be placed at the top of the structure and the Create MUR Wall dialogue settings enabling that are shown below. Please note, that in this case and in the case of absorbing wall at Y2= 32.512 mm, the wall activity is set to MINUS.

Create MUR Wall dialogue for absorbing wall at the top of the microstrip line filter.

For better visualisation we hide the absorber indicator for all MUR Walls by selecting all three MUR walls on the Tree View, and changing Show Absorber in the View tab in Property Editor to false.

Microstrip line filter with three absorbing walls (blue) inserted.