branchline coupler

I m modeling an antenna with a branch line coupler connected to it.Using Mgrid Layout. Feed is given to one port of the coupler. How I can give 50 Ohm termination to the other port of the coupler ?

You can define a port there. Then, you can terminate to 50-ohms or whatever termination you want on MODUA or MGRID in visualizating the current and doing the pattern calculation.