A 3D-printed circularly polarized cavity-based slotted waveguide antenna for kidney cancer detection application

Here are the main highlights of the paper: • A novel design of a circularly polarized (CP) slot antenna is presented based on a waveguide cavity-resonator for kidney cancer detection applications. • A capacitive iris is used to couple the cavity to the input port to create a strong coupling, resulting in better impedance matching than a conventional slotted waveguide antenna. • An L-shaped radiating slot is configured from two orthogonal linearly polarized (LP) slots and is placed on the broad-wall of the cavity to generate CP radiation. • The L-shaped slot dimensions are manipulated to enlarge the axial ratio bandwidth (ARBW). • A prototype has been fabricated using 3D printing technology to validate the predicted results. • The measured 10-dB fractional bandwidth (FBW) is 7.4 % at the center frequency (f0) f0 = 10 GHz. The 3-dB ARBW and peak gain are 7.0 % and 7.5 dBic at 10 GHz, respectively. • The proposed antenna can accurately distinguish between normal and cancerous cells, making it a good candidate for detecting cancer cells in the kidney. This paper presents a novel circularly polarized (CP) slot antenna based on a waveguide cavity resonator for kidney cancer detection applications. The cavity is coupled to the input port via a capacitive iris, ensuring strong coupling and improved impedance matching compared to conventional waveguide slot antennas. An L-shaped radiating slot, formed by two orthogonal linearly polarized (LP) slots, is etched into the broad wall of the cavity to generate CP radiation. The axial ratio bandwidth (ARBW) is enhanced by optimizing the slot dimensions. To validate the predicted results, a 3D-printed prototype was fabricated and tested. The measured 10-dB fractional bandwidth (FBW) is 7.4 % at the center frequency ( f 0 ) f 0 = 10 GHz, while the 3-dB ARBW and peak gain are 7.0 % and 7.5 dBic, respectively. The detection capability of the proposed antenna is evaluated in a modeled measurement system, revealing a calculated sensitivity of 0.175 GHz/RIU at f 0 =10 GHz. Furthermore, the antenna exhibits a resonance frequency shift of 0.21 GHz when tested with renal cancer cells, distinguishing them from normal cells. These findings demonstrate that the proposed antenna effectively distinguishes between normal and cancerous kidney cells, making its potential as a good candidate for kidney cancer detection.