Carbon fiber veil-based lightweight frequency-selective metamaterial with integrated absorption-transmission to electromagnetic waves and preparation method thereof

A carbon fiber veil-based frequency-selective metamaterial with integrated absorption-transmission to electromagnetic waves, comprising:

• a symmetric structure composed of n × n units arranged periodically;
• wherein n is a positive integer;
• each of the n × n units comprises a first frequency-selective metastructure layer, a dielectric layer, and a second frequency-selective metastructure layer laminated in sequence from bottom to top;
• and the second frequency-selective metastructure layer is a lossy frequency-selective metastructure layer;
• a unit structure of the first frequency-selective metastructure layer has a square-ring shape having an outer-side length a115-23-23of 15.23-23.71 mm and an inner-side length a29-14of 9.10 -14.33 mm, and a2 < a1;
• the unit structure of the first frequency-selective metastructure layer is fabricated by laminating a first carbon fiber veil having a sheet resistance of 3-5 Ω/sq and an areal density of 40-80 g/m2 with a first quartz fiber fabric/epoxy composite;
• a center of the unit structure of the first frequency-selective metastructure layer has a square-shaped recess with the first carbon fiber veil removed to expose the first quartz fiber fabric/epoxy composite, such that the square-shaped recess is surrounded by peripheral edges covered with the first carbon fiber veil;
• the first frequency-selective metastructure layer has a reflection behavior similar to that of a perfect electric conductor within an absorption band, and offers a transmission effect within a transmission band via an inductor-capacitor (LC) parallel resonance;
• a unit structure of the dielectric layer is square, and has a side length of a1 and a thickness h3-20-9of 3.20-9.16 mm;
• in response to a case that h varies within a range of 3.20-9.16 mm, an absorption band and a transmission band of the frequency-selective metamaterial remain near a series resonance point of the second frequency-selective metastructure layer and a parallel resonance point of the first frequency-selective metastructure layer, respectively;
• the dielectric layer is made of a polystyrene foam board;
• a unit structure of the second frequency-selective metastructure layer has a cross shape, and has a unit size of b, b=a1 an arm length b115-00-20 of 15.00-20.75 mm and an arm width b21-51-3of 1.51-3.25 mm, wherein b2 < b1 < b;
• the unit structure of the second frequency-selective metastructure layer is fabricated by laminating a second carbon fiber veil having a sheet resistance of 4-25 Ω/sq and an areal density of 5-50 g/m2 with a second quartz fiber fabric/epoxy composite;
• the unit structure of the second frequency-selective metastructure layer has a cross-shaped protrusion formed by removing the second carbon fiber veil within peripheral regions to expose the second quartz fiber fabric/epoxy composite;
• the second frequency-selective metastructure layer achieves impedance matching through LC series resonance within the absorption band, and offers a transmission effect via LC parallel resonance within the transmission band;
• and
• the second frequency-selective metastructure layer as a top layer and the first frequency-selective metastructure layer as a bottom layer are configured to jointly produce parallel resonance within the transmission band to enable effective transmission of the electromagnetic waves.