30results about How to "Good polarization stability" patented technology

A composition for forming a PZT-based piezoelectric film formed of Mn-doped composite metal oxides is provided, the composition including: PZT-based precursors containing metal atoms configuring the composite metal oxides; a diol; and polyvinylpyrrolidone, in which when a metal atom ratio in the composition is shown as Pb:Mn:Zr:Ti, the PZT-based precursors are contained so that a metal atom ratio of Pb is satisfied to be from 1.00 to 1.20, a metal atom ratio of Mn is satisfied to be equal to or greater than 0.002 and less than 0.05, a metal atom ratio of Zr is satisfied to be from 0.40 to 0.55, a metal atom ratio of Ti is satisfied to be from 0.45 to 0.60, and the total of Zr and Ti in a metal atom ratio is 1.

The invention discloses a fractal-element-based frequency selective surface structure which comprises a first frequency selective surface layer and a first dielectric plate, wherein the first frequency selective surface layer comprises a plurality of patch elements; each patch element comprises a first fractal ring, a second fractal ring, a third fractal ring and a fourth fractal ring; the first fractal ring is a regular triangle ring; each side is provided with a U-shape bending part; the second fractal ring, the third fractal ring and the fourth fractal ring are located in the regular triangle ring and are in rotational symmetry distribution about the center of the regular triangle ring; the second fractal ring, the third fractal ring and the fourth fractal ring are quadrangle rings; the first vertex angle, the second vertex angle and the third vertex angle are 120 degrees, 90 degrees and 90 degrees in sequence; the fourth vertex angle is opposite to the first vertex angle; and two sides of the fourth vertex angle are provided with the U-shaped bending parts respectively. The frequency selective surface structure disclosed by the invention has good polarization stability; and the wave-transmitting characteristic can be effectively improved on the basis of keeping the wave-absorbing characteristic. Furthermore, the invention further discloses a frequency selective surface structure-based window absorber.

The invention brings forward a broadband wave absorbing material with stable polarization, for solving the technical problems of poor polarization stability and not wide low-band bandwidth existing in a conventional wave absorbing material. The broadband wave absorbing material comprises a wave absorbing structure (1), an upper medium plate (2), a foam layer (3), a lower medium plate (4) and a frequency selection surface (5), wherein the wave absorbing structure (1) is printed on the upper surface of the upper medium plate (2), the frequency selection surface (5) is printed on the lower surface of the lower medium plate (4), the upper medium plate (2), the foam layer (3) and the lower medium plate (4) are successively arranged to form an up-down stacked structure, the wave absorbing structure (1) is formed by periodically arranging M*N metal broken line units (11) of dead square structures, and the frequency selection surface (5) is formed by periodically arranging M*N frequency selection surface units (51). The polarization stability is high, the absorption frequency band width is wide, the wave absorbing feature is high, the transmission feature at a high frequency is good, and the broadband wave absorbing material with stable polarization can be applied to such fields as antenna communication and absorption shielding and the like.

The invention discloses a dual-frequency FSS with closely spaced frequency response characteristics and a unit structure thereof, the unit structure includes a metal layer and a dielectric substrate, the metal layer is arranged on the dielectric substrate; the metal layer includes a bow A shape ring-shaped metal patch and a square ring metal patch, wherein the square ring metal patch surrounds the outer circumference of the bow-shaped ring metal patch, and the square ring metal patch is The center coincides with the center of the bow-shaped annular metal patch; the bow-shaped annular metal patch is connected end to end by a plurality of bow-shaped metal units to form a center-symmetric annular structure. The dual-frequency FSS includes M×N periodically arranged unit structures. The dual-band FSS has dual-band band-stop characteristics, which can achieve band-stop effects on the frequency bands 5.59-6.51GHz and 7.43-9.61GHz at a depth of ‑10dB, with excellent polarization stability and angular stability, and a small size , to meet the needs of device miniaturization.