Microwave-Based Detection of Early-Stage Renal Cell Carcinoma Using UHF Range Antenna

The research findings demonstrate that the presence of a tumor significantly affects the reflection coefficient and resonance frequency. In cases of early-stage cancer, the reflection coefficient (S 11) increases, and there is a discernible shift in the resonance frequency, which can be used to identify cancer. For exhibiting the study, we have designed and implemented a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2 \times 2$</tex> rectangular patch antenna array that functions at a specific frequency of 3.7 GHz in the UHF range. The array dimensions are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$122 ~\text{mm} \times 123.8 ~\text{mm}$</tex>, and each patch measures 28.3 mm on the side and 37.3 mm in width. The substrate is made of FR-4 material, with a relative permittivity of 4.3, a thickness of 1.6 mm, and a metal layer thickness of 0.035 mm. The performance of the antenna has been analyzed using a renal system phantom used in the study, which replicates the cortex, renal fascia, renal capsule, muscle, fat, and skin, along with other kidney tissues. The crucial aspect of detecting cancer is the antenna's capability to detect changes in the dielectric properties of kidney tissues through monitoring its frequency response. In results we have seen that the reflection coefficient increases 9.14427 % from healthy to stage 1 and 12.4498 % from stage 1 to stage 2. And the resonant frequency shifts from 3.7585 GHz in healthy tissue to 3.757 GHz in stage 1 and 3.7525 GHz in stage 2.