How disign two coax antenna with same refrence- cst

Hi Dear All
Any one know how i can disign an antenna with two coax cable far away but outer sheild of both of them connected to ground.
just one of them has sorce. I have problem to understand the refrence (as ground) that is common in both coax.
tanx

May be you can use: Macros - construct - discrete ports - multiple discrete ports. But I'm not sure, that is answer on your question.....