I think you're misunderstanding something.
Miracast is a GRAPHIC CARD standard. Not a CPU. Ryzen or CoreI cpus have nothing to do with Miracast. FYI both AMD and INTEL iGPUs on their cpus supposedly support Miracast. Miracast requires a display adapter which supports Windows Display Driver Model (WDDM) 1.3 which to the best of my knowledge includes all current AMD and NVIDIA GPUs, it also requires and a Wi-Fi adapter that supports Wi-Fi Direct;
Just be careful about your WIFI adapter and you should be able to make it work.
THAT SAID -
from a little research I've noticed while NVIDIA claims support for WDDM 1.3 and Miracast, it turns out nvidia actually cut support for Miracast back in 2016; meaning you'd need some of their...