Adding ports to know resistance at some point in 2-patch antenna

Hi, how to I calculate the resistance at some point on the patch antenna, I added 1 source lumped port of 100ohm at one end of the feed line, how to calculate the resistance at the end of the feed line that id attached to the patch?

For 100 Ohm lumped port if you measured some S11:

Z=100*(1+S11)/(1-S11)

For example, you've obtained Z11 = 153.2 - i*1.912578972
Now if we ignore small complex part and set lumped port impedance to 153 Ohm, there will be a good matching.
Also you may add quarterwave transformer from 50 Ohm to 153 Ohm and set lumped port to 50 Ohm to see if it matches correctly.