Rectangular microstrip radiator for a multielement local hyperthermia applicator

An effective local hyperthermia applicator should deliver controlled wave energy to anatomic sites so as to safely heat a tumor while leaving normal tissue unharmed. A multielement microstrip array can provide such control and has the advantage of a thin, lightweight, conformable structure that can heat sites in the chest-wall, abdominal and pelvic regions more efficiently. An important component of the design is a low-loss dielectric cover layer that increases the cavity resonance (Q) of a rectangular microstrip patch radiating into a biological medium. Impedance matching and radiated electric-field pattern characteristics are also improved by the cover layer for the goal of hyperthermia application. The choice of substrate dielectric constant is discussed as a major consideration in multielement microstrip array design.<>