Large-bandwidth and small-size periodic unit frequency selective surface structure

Abstract

A large-bandwidth and small-size periodic unit frequency selective surface structure comprises a first base material and a second base material. An upper conducting layer is arranged on the front face of the first base material, a middle conducting layer is arranged between the first base material and the second base material, a lower conducting layer is arranged on the back face of the second base material, and the upper conducting layer, the middle conducting layer and the lower conducting layer are formed by periodically arranging upper periodic units, middle periodic units and lower periodic units respectively, each upper periodic unit is formed by a broken line on the left side and an upper-layer first conducting metal sheet and an upper-layer second conducting metal sheet, wherein the upper-layer first conducting metal sheets and the upper-layer second conducting metal sheets are located on the right side. The middle periodic units are formed by middle-layer conducting metal sheets, each lower periodic unit is formed by a series of lower-layer parallel conducting metal wires, the periodic units on all layers are the same in size and are arranged vertically in an overlapped mode, and the edges of the periodic units are aligned. According to the large-bandwidth and small-size periodic unit frequency selective surface structure, face-to-face coupling of the conducting metal sheets is used, distributed capacitance is enhanced, and the relative size is reduced; the broken lines enhance the distributed capacitance and increase the relative passband bandwidth; the lower-layer parallel conducting metal wires enhance the frequency selective surface cross polarization isolation.

Description

technical field [0001] The invention belongs to the field of frequency selective surface design, and in particular relates to a frequency selective surface structure of a period unit with a large bandwidth and small size. Background technique [0002] Frequency selective surface has gradually become a research hotspot due to its application value in antenna, microwave and other fields. Frequency selective surfaces are composed of one-dimensional or two-dimensional periodic structures whose transmission coefficients behave as spatially structured filters. The miniaturization of the periodic unit size (expressed as the relative size of unit side length and resonant frequency wavelength) of frequency selective surface is a very important research direction of frequency selective surface. The smaller the element size, the weaker the grating lobe characteristics of the frequency selective surface, and the transmission coefficient will be about stable under the condition of large...

AI Technical Summary

Problems solved by technology

Although the above method can significantly reduce the cell size, due to the relative bandwidth of the frequency selective surface When C increases significantly, the relative bandwidth will gradually decrease

Therefore, the above cell size miniaturization techniques are of limited use in the design of large relative bandwidth frequency selective surfaces without loading with lumped inductive elements

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