Perfect mirror with HFSS

Hello every body
It?s the first time that I use HFSS. So may be my question will be very easy for you.
When I send the plane wave to my structure, I want after the propagation in this structure until the end, the wave turns back as if there is a perfect mirror. I was thinking in perfect conductor.

you can draw a 2D rectangle and assign boundary (Perfece E)

thank you for your answer, I will tray your solution. But what is the difference between perfect E and perfect conductor.
For me I'm not shower that assign boundary (Perfect E) will reflect the incident wave. First of all, if the direction of my wave port is perpendicular to the boundary (Perfect E) the result will be 0, and not reflected wave.

because the wave is parallel to the boundary,

I advise you to read a book on basic electromagnetism like (Engineering electromagnetics)