Design of an Omega Phi-shaped Tri band metamaterial absorber with sensing application

This paper introduces an innovative tri-band metamaterial absorber designed for advanced sensing applications, demonstrating significant achievements in electromagnetic absorption and sensitivity across multiple frequencies. The proposed metamaterial absorber operates effectively at targeted resonant frequencies of 2.46 GHz, 6.25 GHz, and 12.45 GHz, exhibiting excellent reflection coefficients, indicating reduced energy loss and enhanced signal integrity at these frequencies. The compactness of the design is achieved through accurately calculated unit cell dimensions of 0.121${\lambda }_0$ × 0.121 ${\lambda }_0$, where ${\lambda }_0$ is the wavelength at a resonance frequency of 2.46 GHz, resulting in a total size of 18 × 18 mm2. One of the most notable features of this proposed design is the high absorption rate, achieving up to 99.99 % at its operational frequencies. The proposed design was validated numerically and experimentally, ensuring the theoretical models accurately predict practical behavior. The design also offers substantial flexibility for frequency-selective applications in sensing technology, enhanced by the sensor’s high sensitivity. This sensitivity was thoroughly verified using food color-water mixtures with concentrations up to 99.99 %, effectively demonstrating the metamaterial absorber’s ability to respond to the changes in dielectric properties with shifts in resonant frequencies that perfectly match theoretical expectations. Therefore, the proposed metamaterial absorber is an efficient solution for modern sensing challenges.