A compact structure of four half-circle resonator metasurfaces for microwave sensing applications

This work presents a simple and compact quadrilateral half-circle resonator metasurface for microwave sensing applications. The metasurface (MTS) unit cell exhibits carrier resonance surface characteristics for the K-band. It has an excellent absorption response at f_o = 21.45 GHz and at f_o = 23.04 GHz, indicating its coherence and efficiency. The proposed unit cell was developed for sensing applications to detect the sensitivity of liquid or solid materials within an electromagnetic simulation environment at K-band. The sensing methods are investigated to determine which is more effective for measuring sensitivity and its potential in microwave sensing. The resonance frequency fluctuates based on permittivity and refractive index. The MTS unit cell amplifies this resonance using electric field intensity. The measured results demonstrate that the proposed metasurface has excellent sensitivity, a high Q-factor (Q > 55), and a strong Figure of Merit (FoM). The good sensitivity, Q-factor, and FoM results indicate that the proposed MTS is a viable solution for microwave sensing applications.