Tunable frequency selective surface structure
Provided is a tunable frequency selective surface (FSS) structure, including: a dielectric substrate and a rectangle resonant component arranged on the dielectric substrate. The rectangle resonant component includes a plurality of perforated rectangle resonant units arranged in a matrix; the perforated rectangle resonant units each include two identical rectangle perforated metal patches, and a varactor diode arranged between the two rectangle perforated metal patches, where the two rectangle perforated metal patches are arranged in a mirror image relation. In the rectangle resonant component, the varactor diodes in the perforated rectangle resonant units in the same row are arranged in a same direction, and the varactor diodes in the perforated rectangle resonant units in adjacent rows are arranged in opposite directions. The present application can achieve the continuous tunable performance of a stopband in a specific frequency band.
1 . A tunable frequency selective surface (FSS) structure, comprising:
a dielectric substrate and a rectangle resonant component arranged on the dielectric substrate, wherein
the rectangle resonant component comprises a plurality of perforated rectangle resonant units arranged in a matrix;
the perforated rectangle resonant units each comprise two identical rectangle perforated metal patches arranged in a mirror image relation, and a varactor diode arranged between the two rectangle perforated metal patches; and
in the rectangle resonant component, the varactor diodes in the perforated rectangle resonant units in a same row are arranged in a same direction, and the varactor diodes in the perforated rectangle resonant units in adjacent rows are arranged in opposite directions;
wherein the rectangle perforated metal patches are each provided with a first rectangle hole, a second rectangle bole, and a third rectangle hole; and the first rectangle hole and the second rectangle hole are symmetrically arranged on two sides of the third rectangle hole;
wherein the first rectangle hole comprises two parallel transverse edges and two parallel vertical edges;
the second rectangle hole comprises two parallel transverse edges and two parallel vertical edges,
the third rectangle hole comprises two parallel transverse edges and two parallel vertical edges:
one end of a first transverse edge of the third rectangle hole is connected to one end of a first transverse edge of the first rectangle hole, the other end of the first transverse edge of the third rectangle hole is connected to one end of a first transverse edge of the second rectangle hole and the first transverse edge of the third rectangle hole, the first transverse edge of the first rectangle hole and the first transverse edge of the second rectangle hole are located on a same horizontal line;
one end of a second transverse edge of the third rectangle hole is connected to one end of a second transverse edge of the first rectangle hole, the other end of the second transverse edge of the third rectangle hole is connected to one end of a second transverse edge of the second rectangle hole, and the second transverse edge of the third rectangle hole, the second transverse edge of the first rectangle hole and the second transverse edge of the second rectangle hole are located on a same horizontal line; and
a first vertical edge of the third rectangle hole and a first vertical edge of the first rectangle hole are the same, and a second vertical edge of the third rectangle hole and a first vertical edge of the second rectangle hole are the same.
2 . The tunable FSS structure according to claim 1 , wherein the rectangle perforated metal patches each further comprise a first extended edge and a second extended edge;
the first extended edge is an edge passing through a first marking end to extend outward, and the second extended edge is an edge passing through a second marking end to extend outward;
the first marking end is the other end of the first transverse edge of the first rectangle hole, and the second marking end is the other end of the first transverse edge of the second rectangle hole; and
in the rectangle resonant component, the perforated sept rectangle resonant units in the same row are connected together through the first extended edge and the second extended edge, such that the varactor diodes in a same row are in parallel connection.
3 . The tunable FSS structure according to claim 2 , further comprising a first feed metal wire and a second feed metal wire, wherein
the first feed metal wire is connected to one end of a first marking extended edge in the perforated rectangle resonant units in a first column of the matrix, and the second feed metal wire is connected to one end of a second marking extended edge in the perforated rectangle resonant units in a last column of the matrix;
the perforated rectangle resonant units each comprise a first rectangle perforated metal patch and a second rectangle perforated metal patch; when the perforated rectangle resonant units are located in odd-numbered rows of the matrix, the first marking extended edge is a first extended edge of the first rectangle perforated metal patch, and when the perforated rectangle resonant units are located in even-numbered rows of the matrix, the first marking extended edge is a first extended edge of the second rectangle perforated metal patch; when the perforated rectangle resonant units are located in odd-numbered rows of the matrix, the second marking extended edge is a second extended edge of the second rectangle perforated metal patch, and when the perforated rectangle resonant units are located in even-numbered rows of the matrix, the second marking extended edge is a second extended edge of the first rectangle perforated metal patch; and
in an operation process, when the varactor diodes have anodes connected to the first rectangle perforated metal patch and cathodes connected to the second rectangle perforated metal patch, when the first feed metal wire is connected to a positive pole of an external power supply, the second feed metal wire is connected to a negative pole of the external power supply, and when the varactor diodes have anodes connected to the second rectangle perforated metal patch and cathodes connected to the first rectangle perforated metal patch, when the first feed metal wire is connected to the negative pole of the external power supply, the second feed metal wire is connected to the positive pole of the external power supply.
4 . The tunable FSS structure according to claim 1 , wherein the transverse edges of the first rectangle hole and the transverse edges of the second rectangle hole are all 1 mm long; the transverse edges of the third rectangle hole are 4 mm long; the vertical edges of the first rectangle hole and the vertical edges of the second rectangle hole are all 4.3 mm long; and the vertical edges of the third rectangle hole are 3.8 mm long.
5 . The tunable FSS structure according to claim 1 , wherein the varactor diodes have a capacitance range of 0.3-2.22 pF; and the varactor diodes have an on-load voltage range of 0-20 V.
6 . The tunable FSS structure according to claim 1 , wherein the perforated rectangle resonant units each have dimensions of 16 mm×10 mm, and the rectangle perforated metal patches each have dimensions of 8 mm×4.6 mm.
7 . The tunable FSS structure according to claim 1 , wherein in the perforated rectangle resonant units, every two of the rectangle perforated metal patches have a gap of 0.4 mm, and the varactor diodes are located at the gaps.
8 . The tunable FSS structure according to claim 1 , wherein the dielectric substrate is an FR4 substrate, and has a thickness of 0.4 mm.