design waveguide port for aperture coupled antenna microstrip

hello
I want to simulate the aperture coupled micro-strip antenna, and i have the parameters of this antenna, just i want to know how to design waveguide port, i tried to use 3*wf X mt+5*hp:wf is width of feed line,and hp: high of substrate of patch,
but for microstrip antenna,you know in this antenna, the feed line and patch are on the same substale,but in my antenna,aperture coupled microstrip antenna , the feed line and patch are not on the same substrate, each one has propre,order such as: patch with tp as thin,subtrate of patch with hp, puis gound plan with tg,then substrate of feed line with hf, finally the feed line with tf and witdh wf
so I hope you will help me how to design the waveguide port with these values (tp,hp,tg,Hf,tf)