[CST] how can i use probe for detecting?

hi guys,
i wanna use periodic boundary but i don't know much about probe detecting. seems that a probe can only detect the signal on one point. but i need the sum of the signal on a surface. i don't know how to do it without set a waveguide port. so i hope somebody could know how to do it. THx!

Hi.
There is an option in "Template based postprocessing"(Shift+P)->"0D results"->"Add new postprocessing step"->"Evaluate field on predefined face"
But I don' know much about this function, so I don know whether you can use it. GL

Thx for your reply, i will try your method and hope it could work