Slotted Waveguide Circular Arc Array Terminated in A Bio-medium for Hyperthermia

A novel and effective hyperthermia applicator utilizing a circular arc phased array of longitudinal slots in narrow wall of rutile-loaded rectangular waveguide is presented and analyzed in this paper. This configuration is mainly intended as a specialized and very effective applicator for hyperthermia treatment of tumor within curved portions of human body such as abdomen, neck, chest etc. Each slot is excited by a coaxial line probe. The expression for electric field in biomedium due to slotted waveguide arc array is derived utilizing Fresnel-Kirchhoff scalar diffraction field theory. The contour distribution of specific absorption rate (SAR) in x-z, x-y and y-z planes and SAR distribution in y-direction due to the arc array as direct contact applicator are evaluated at 433 MHz. The parameters such as penetration depth, power absorption coefficient, effective transverse field size (TFS), effective longitudinal field size (LFS) are obtained for the arc array. It is shown that by changing the phase and amplitude of excitation of each slot of the array, relative shape (TFS) and position of the hot spot can be changed.