Calculate the raduis of circulair patch antenna

Hello, i calculate the raduis of circulair patch antenna using the formula bellow, i have fr=28GHz; h=0.15mm; εr=2.2
and i get raduis=0.17mm, please is it a correct value or not?

Have you got an EM solver? Draw a circular with the parameters as shown and see if it resonates at the desired frequency. This will validate the reliability of the formula as well.

Does the text include calculating the position of the input port too?