Field consideration of focusing waveguide applicator for deep microwave hyperthermia / Harun Mohamed

Microwave hypothermia using waveguide appplicators has gained popularity because of the desirable heating characteristic of this type of heating modality. This project investigates the feasibility of using Dielectric Open-ended Rectangular Waveguide Direct-contact Antenna (DORWDA) array for depositing microwave energy into the human body for heating deep-seated tumours. A distilled water-loaded DORWDA array applicator with a small aperture size (1.75 X 10.3 cm ) has been developed for deep hyperthermia applications. The operating frequency is chosen to be 915 MHz. The water loading provides a good coupling of radiated power into tissues. The observed variation in standing wave ratios and the concentration of the fields are found to be satisfactory for localized deep hyperthermia treatments. Analytically, the near field distributions inside the human muscle are obtained by using the Kirchoff-Huygens principles and scalar theory of diffraction. The obtained field patterns may only be moderately focused, but these are me optimun for the present applicator.