Benzene Structure-Based Circularly Polarized Beam Reconfigurable Antenna for Microwave Imaging-Based Biomedical Applications
Rajesh Yadav, Shailza Gotra, V. S. Pandey, Sandeep Kumar, Ajay Kumar Sharma
Abstract
A beam scanning circularly polarized microstrip antenna of benzene-shaped structure has been designed and developed. The antenna comprises of radiating element, FR-4 epoxy substrate, and ground plane. The radiating elements have been made up of perfect electric conducting material, which is placed above the substrate, while the ground plane is arranged in a periodic grid fashion line arrangement. The antenna is excited by a 50-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $</tex-math> </inline-formula> single-fed line connected to the radiating element. The proposed antenna is resonating at 3.57GHz, demonstrating significantly improved the return loss, gain, axial ratio (AR), and so on. The maximum gain and efficiency of the proposed antenna have been obtained as 4.52 dB and 52.21%, respectively. Furthermore, the radiation pattern of the proposed antenna has been reconfigured by changing the configuration of the ground plane structure. The antenna provides the maximum beam scanning <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$- 150^{\circ } \le \theta \le + 150^{\circ }$</tex-math> </inline-formula> due to the different ground plane configurations. The circular polarization (CP) (AR <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\le 3$</tex-math> </inline-formula> dB) is obtained due to the generation of orthogonal degenerate modes. The measured and simulated results are found in the better agreement with each other. Furthermore, a parametric analysis has been conducted to optimize the outcomes. The proposed antenna is utilized for tumor detection applications, which include enhanced imaging resolution, deeper tissue penetration, and reduced scanning time along with the optimized radiation characteristics required for efficient microwave imaging systems.