Frequency selective surface unit, frequency selective surface structure, electronic device and radome

A frequency selective surface unit, comprising:

• at least one dielectric substrate;
• at least one first resonant pattern, wherein a first resonant pattern is disposed on a dielectric substrate, and each of the at least one first resonant pattern includes a plurality of protruding portions;
• and
• at least one second resonant pattern, wherein a second resonant pattern is disposed on the dielectric substrate, and the second resonant pattern and the first resonant pattern have a distance therebetween in at least one of a direction parallel to a plane where the dielectric substrate is located and a direction perpendicular to the dielectric substrate;
• wherein the second resonant pattern is a serpentine structure, and the serpentine structure includes a plurality of first extending portions and a plurality of second extending portions;
• the plurality of first extending portions are parallel to each other, an extension direction of the plurality of first extending portions intersects an extension direction of the plurality of second extending portions, and two adjacent first extending portions are connected to each other through a second extending portion;
• the second resonant pattern and the first resonant pattern are disposed on two opposite surfaces of the dielectric substrate in the direction perpendicular to the dielectric substrate, respectively;
• and an orthographic projection of the first resonant pattern on the dielectric substrate partially overlaps with an orthographic projection of at least one first extending portion on the dielectric substrate;
• and
• a width of each first extending portion and a distance between two adjacent first extending portions are equal.