a direct contact microwave diathermy applicator consisting of a rectangular waveguide in which are secured two parallel teflon dielectric loading slabs . this assembly is secured in a waveguide - coaxial cable adaptor , enabling the applicator to be energized from a microwave diathermy machine . the configuration of the applicator causes the tissue under treatment to exhibit approximately uniform heating patterns over a substantial portion of the treated tissue area and minimizes harmful scatter radiation . this uniform heating is particularly useful in effecting microwave induced hyperthermia treatment of cancer .