Microwave absorbers find their use in various applications, including the design of stealth systems, electromagnetic interference (EMI) shielding, and imaging technologies. To effectively use absorbers as an imaging tool, the two options available are (a) bolometer with resistance measurement and (b) bolometer coupled with thermal imaging. With the limitations of designing flat homogenous materials to absorb > 90%, it is possible to enhance the collection efficiency of the microwave radiation and improve the overall sensitivity. Instead of using a conventional lens system, designing a metamaterial (MM) flat lens that effectively focuses the microwave beam onto the absorber is better.

In this study, we explore the integration of an MM lens to improve the thermal response and bolometer-based imaging capabilities of a microwave absorber. We thus develop a suitable MM lens model to couple with the polymer nanocomposite (carbon nanotubes – polyvinylidene) absorber.

This paper presents the design of an MM lens-integrated microwave absorber. A multi-physics simulation software, COMSOL, with its Electromagnetic Waves and Heat Transfer in Solids modules, is employed to design the MM lens and obtain the heating pattern of the custom-developed absorber. Furthermore, the feasibility of using such an enhanced absorber system for imaging applications, including potential benefits in spatial resolution and imaging quality, is explored.