Polarization-Insensitive and Oblique Incident Angle Stable Miniaturized Conformal FSS for 28/38 GHz mm-Wave Band 5G EMI Shielding Applications

This letter presents a miniaturized conformal dual-band mm-wave frequency selective surface (FSS) for fifth-generation (5G) electromagnetic interference (EMI) shielding applications. Two back-to-back resonators are separated with a 0.254 mm thin dielectric substrate. The proposed FSS exhibits two wide stopbands (
S
₂₁
<−10 dB) in the mm-wave 5G frequency spectrum. The stopband bandwidths are 42.8% at 28 GHz and 24.2% at 38 GHz. The periodicity of the unit cell is 0.26λ
₀
, where λ
₀
is the wavelength of the lower stopband. The key features of the proposed FSS include a miniaturized unit cell structure for 28 and 38 GHz frequency bands with a high oblique incident angle stable filter behavior up to 60°. The proposed FSS also features polarization insensitivity and conformality. The simulated and measured results show good agreement for EMI shielding applications.