Single-Layered Flexible Multiband Rasorbers

In the preceding chapter, a T-A-T-type rasorber was presented, featuring a single narrowband absorption between two transmission bands, implemented on a 0.8 mm thick substrate. While effective in demonstrating the T-A-T response, the design offered only single-band absorption and did not meet the physical thickness constraints required for conformal or flexible platform integration. In this chapter, advanced A-T-T-A- and A-T-A-T-A-type rasorbers are proposed, fabricated on an ultra-thin 0.25 mm flexible substrate. The A-T-T-A configuration achieves dual-band transmission and dual-band absorption (2T2A) by combining a dual-resonant frequency selective surface (FSS) absorber with a dual-bandpass FSS on opposite sides of a single dielectric layer. To enhance functionality, an additional resonant structure is incorporated, resulting in an A-T-A-T-A configuration that exhibits dual-band transmission and triple-band absorption (2T3A). These proposed rasorber designs are ultra-thin, polarization-insensitive, single-layered, and conformal, making them highly suitable for practical stealth applications.