[moved] hyperthermia applicator (antenna, cst)

I had made a double coaxial slot antenna at 915 MHz in CST microwave studio, the problem is with the feed as it is a cylindrical antenna the problem is with the feed. I had given it waveguide feed but the results are not coming appropriate.how to the cylinderical antenna feed and where should be the ground plane.there is a tip at the bottom of the cylinder

i had made a coaxial double slot antenna and had feed it with waveguide port, i want a power output of 10 watt at tip of the antenna.can somebody tell me the procedure for discrete port to this type of antenna