Double Sided Band-pass Frequency Selective Surface Based on Matryoshka Geometry

Abstract This paper describes the development of a double-sided band-pass frequency selective surface based on Matryoshka geometry, preserving features such as miniaturization, multiband operation and stability of polarization and angle of incidence. Unlike cascaded FSSs, the proposal uses only one layer of substrate, with Matryoshka geometry on one side and a square mesh on the other, reducing volume and simplifying manufacturing by avoiding spacers. The double-sided FSS allows the frequency response to be adjusted using the geometry of the opposite face, which in this work is a square loop. With an attenuation of -10 dB, the proposed configuration offers a free band from 3.48 GHz to 9.06 GHz, compared to the original configuration, which ranged from 5.88 GHz to 7.43 GHz, with only 1.55 GHz free. Initial design equations are presented which facilitate the creation of FSSs for other frequencies and applications. An FSS has been designed, fabricated, and characterized, with good agreement between numerical and experimental results. The resonant frequency remains practically constant for different incidence angles, from 0º to 60º, confirming the angular stability.