Design and Tensor Impedance Analysis of 4 × 4 Isotropic Homogeneous Metasurface-Backed Slotted Dual-Layered Bio-Superstrate-Loaded MPA

A 4 × 4 Isotropic Homogeneous Metasurface (IHM) backed, rectangular slotted dual-layered triband microstrip patch antenna (MPA) is proposed in this article. A detailed mathematical way to analyze the tensor surface impedance matrix (TSIM) of the proposed 4 × 4 IHM and slotted patch is demonstrated. The proposed IHM-backed MPA has a triband even-mode resonance at f_r0 = 2.45 GHz, 2f_r0 = 5.4 GHz, and 4f_r0 = 7.7 GHz. A better and more accurate estimation of bio-superstrate loading effect for triband resonance is employed using the human skin (ε_r = 52.79, σ_s = 1.39) and blood (ε_r = 52.8, σ_s = 1.23) layer on the top of dual-layered metasurface-backed slotted MPA. TSIM characterization is observed for both blood- and skin layer-loaded dual-layered metasurface-backed slotted MPA. Chicken breast (ε_r = 55.2, σ_s = 1.49, and tanδ = 0.325) with blood (ε_r = 58.2, σ_s = 2.59, and tanδ = 0.364) is loaded onto fabricated dual-layered structure to verify numerically modeled estimation. A closed form triband, even-order resonance mode (i.e., f_r0, 2f_r0, and 4f_r0) estimation based on dielectric superstrate thickness (H_s) is numerically established using MATLAB solver. Complete measurement setup with simulated vs. measured results is compared in this article.