Circular arc sectored array of box-horns for therapeutic applications

In this paper, we present analysis and design of circular arc sectored array of water-loaded box-horns for therapeutic treatment of cancer. This array is useful for hyperthermia treatment of tumor within curved portion of body such as neck, arms etc. It is assumed that the box-horn is loaded with water to provide good impedance match to bio-medium. Also, it reduces the size of box-horns for it to be useful for array configuration. An analytical model is reported in which the values of specific absorption rate (SAR)/contour of SAR distribution in heating medium (muscle/tumor) due to array of box-horns are evaluated at 2.45 GHz. The penetration depth and power absorption coefficient are computed for the sectored array. The present analysis is carried out using Fresnel-Kirchhoff scalar diffraction field theory. Results have shown that sectored array has wider lateral area of heating pattern in x-y-plane and higher penetration depth in z-direction in comparison to single water-loaded box-horn. It is shown that by changing the phase and amplitude of excitation of each box-horn of the sectored array, relative amplitude and position of the heating spot can be changed. The present theory can be utilized to develop a circular arc sectored array of water-loaded box-horns for hyperthermia treatment of cancer within the curved part of the human body.