Question about mutual coupling for microstrip array?

It's about designing microstrip array with ADS
Instead of using Full wave analysis, we can use Transmission line for microstrip array. Anyone can explain how to investigate the effect of mutual coupling of the patches using TL analysis for microstrip array , which kind of component should be added.

And how we can decide the number of patch to get the best peformance, because more patch we will get more circuit lines, and it means more loss. Is there any theory related to this problem?

if you simulate the microstrip array in the same project, you can directly get the mutual coupling directly(EM simulation).