A microwave antenna assembly is disclosed. The antenna assembly includes a feedline having an inner conductor, an outer conductor and an inner insulator disposed therebetween and a radiating portion including a dipole antenna coupled to the feedline and a trocar coupled to the dipole antenna at a distal end thereof. The antenna assembly also includes a slidable outer jacket disposed about the radiating portion and the feedline. The slidable outer jacket being configured to slide about at least one of the radiating portion and the feedline from a closed configuration, in which the slidable outer jacket is mated with the trocar and a retracted configuration, in which the slidable outer jacket is retracted in a proximally exposing at least a portion the radiating portion.