Multi-Functional Modulated Surface Based on M-Type Ferrite for mmWave Application

This paper presents a multi-functional structure that integrates a modulated surface with an M-type ferrite slab, facilitating beam steering, signal transmission, and electromagnetic absorption for advanced communication and radar systems. To address the limitations inherent in conventional dielectric substrates, M-type ferrite is employed, offering the ability to independently manage frequency-division characteristics across different frequency bands. The modulated surface on the substrate is engineered to simultaneously achieve anomalous reflection at lower frequencies and absorption at higher frequencies. Furthermore, a band-pass frequency selective surface (FSS) is positioned beneath the M-type ferrite, enabling a transmission band without compromising the other functionalities. The efficacy of the modulated surface is validated through fabrication and measurement, demonstrating its performance as an anomalous reflector at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$39 \mathbf{G H z}$</tex>, a band-pass filter at 57 GHz, and an absorber at 77 GHz.