How to model inset line feed for rectangular microstrip patch antennas?

Hello, in CST is there any source that how to model inset line feed for rectangular microstrip patch antennas? In my opinion i draw a brick, put on the patch and substrate, choose its lenght till the end of the substrate and cut the shape.Finally put a new brick and pick face of the new brick in order to define a port.I choose the height of patch nearly 0.5 mm so as the inset brick.Is my opinion right or is there another way?I thought that the port will be too small in order to match the impedance.I hope i could explained clearly.Thanx for your help.

When i do the thing i say above, it gives warning that "high lossy port " and abort simulation.I need help...