Microstrip C patch antenna for hyperthermia treatment: A comparative numerical study with cavity backed C patch antennas

In this study, we present the numerical design of a 434 MHz microstrip C patch antenna for hyperthermia treatment. This design is a microstrip realization of our existing water-loaded rectangular cavity backed patch (RCBP) antenna. Electromagnetic (EM) simulation study is carried out on homogenous tissue model to optimize the antenna design parameters. The performance of the optimized antenna is assessed on heterogeneous model derived from breast cancer patient image data. The microstrip antenna has 36 x 36 mm(2) aperture and an integrated 20 mm thick water bolus. The optimized design on homogenous tissue has >90% power coupling with 9 MHz bandwidth (-10dB) and >80% tangential radiated near field. The tissue specific absorption rate (SAR) of the optimized microstrip patch is higher than our existing RBCP antenna with additional advantages of light weight, low profile and fabrication ease. The antenna assessment on patient derived model also indicated > 90% power coupling and localized SAR in breast fat and fibro glandular tissues with only 1% SAR in costal cartilage and ribs. It is concluded that the low-profile microstrip C patch could be used for hyperthermia applicator design.