Radiation Absorption Distribution of Hyperthermia Rectangular Microstrip Applicator with Three Different Substrates

The effects of rectangular microstrip applicator with three different substrate permittivities toward breast hyperthermia radiation absorption distribution are investigated. The main goal of the research is to determine the best substrate to be used for the applicator development, which contribute toward the capability of the applicator in penetrating deeper, which is about 100 mm depth and also taking into account the focusing effects by reducing the unwanted hot spots at the surrounding healthy tissue. The radiation absorption distribution, which is represented by the specific absorption rate (SAR) with 1 and 10 g weight, are presented and analyzed. The rectangular microstrip hyperthermia applicator is developed with three operating frequencies, namely as industry, scientific and medical (ISM), 434, 915, and 2450 MHz. The operating power is stipulated to 10 W. The substrates to be investigated are FR-4, RT/Duroid 5880, and silicon. The permittivities, ɛr are 4, 2.2 and 11.9, respectively. As predicted, the outcomes of the SAR are different in radiation absorption distribution when different substrates with different permittivities are utilized. The greatest results are presented by the hyperthermia applicator with silicon substrate, if compared to the other two applicators, which is embedded with FR-4 and RT/Duroid 5880, where the penetration depth and focusing toward the targeted area to be treated are achieved.