Modulated Metasurface Loaded Series-Fed Microstrip Patch Antenna Array for Near-field Focusing and Biomedical Applications

In this study, a modulated metasurface (MMS)–loaded 4×1 binomially distributed series-fed patch antenna array (SFPAA), occupying an aperture of 4.2λ0×4.2λ0 is numerically designed to operate at f0=2.4GHz. Comprehensive electromagnetic (EM) simulations are conducted to investigate its near-field (NF) behavior for potential biomedical applications. To ensure high directivity, the proposed SFPAA is fed by a uniformly distributed 1×4 Wilkinson power divider, resulting in a broadside radiation pattern with a peak gain of 13.85 dBi and a sidelobe level (SLL) of 14.97 dB. Upon integration with the MMS, the realized gain improves, achieving a peak value of 16.02 dBi. The near-field characteristics are further analyzed by visualizing the magnitude of the electric field (E-field) on a virtual observation plane positioned at a distance of 0.08λ0 along the +z-axis from the surface of the MMS-loaded antenna module.