Peter Serano
posted this
21 November 2018

- Last edited 21 November 2018
Hi Kerry,

The radiation boundary should be at least lambda/2 away from any outer surface of your antenna (with lambda being based on the lowest frequency point in your sweep).

Instead of using an open region, I would recommend creating a box defined as vacuum with equal dimensions 'rad_box_size' equal to [lambda (at lowest freq point) + max antenna dimension (from the origin)]. Then set the X, Y, and Z lengths of the box to 'rad_box_size' and center it at coordinate '-rad_box_size/2,-rad_box_size/2,-rad_box_size/2' so that the box is centered around the isocenter (where your antenna should be placed).

After you make the box, press 'f' to go into face select mode and select all 6 faces of the box you just created and define the faces as a Radiation Boundary.

You can also now setup a parametric sweep of the variable 'rad_box_size' and see how it effects your results. You should see the sweeps start to converge to the same result as you increase the size of the box towards lambda.

Best,

Peter Serano - Senior Application Engineer - High Frequency Products