Compact Dual-Band Waveguide Band-Stop Filter Using a Metasurface-Embedded Broad Wall

This paper proposes a miniaturized dual-band band-stop filter (BSF) utilizing metasurface integration on the broad wall of a WR-75 rectangular waveguide. The design achieves dual-band suppression within the fundamental TE10-mode pass-band by strategically embedding one or two metasurface elements, enabling precise control over stopband characteristics without compromising wideband transmission efficiency. Simulation results demonstrate that the optimized dual-metasurface configuration delivers a sharp rejection exceeding 30 dB in two target bands while maintaining a passband insertion loss below 0.05 dB. Notably, the filter architecture achieves extreme compactness, while retaining full compatibility with standard waveguide interfaces.