Microwave applicators are disclosed which include a first transmission line segment, a second transmission line segment, and a third transmission line segment. The first transmission line segment includes a first inner conductor, a first dielectric disposed on the first inner conductor, and a first outer conductor disposed on the first dielectric. The second transmission line segment includes a second inner conductor, a second dielectric disposed on the second inner conductor, and a second outer conductor disposed on the second dielectric. The third transmission line segment includes a third inner conductor disposed on the third inner conductor, a third outer conductor disposed on the proximal end of the third dielectric. The impedance looking into the second transmission line segment from the first transmission line segment can be adjusted by adjusting the length of the third transmission line segment.
