PIN diode simulation in Mircowave CST

Hi guys,

Hope every1 doing fine. I have recently started using Microwave studio CST. I want to simulate a PIN diode switch in a Patch antenna. Could any1 let me know how i can simulate it. Some brief explanation would be very beneficial. or any document/ steps are more welcome

thanks in anticiaption

do let me know if u want more details

Cheers