Wideband, wide-angle coding phase gradient metasurfaces based on Pancharatnam-Berry phase

Abstract

A new concept of the coding phase gradient metasurface (CPGM) is proposed, which is constructed using the phase gradient metasurface as the coding elements. Different from the previous coding metasurface (CM), both the coding sequences and gradient phases in the coding elements are designed to manipulate the electromagnetic (EM) wave for the CPGMs, and thus the manipulation will be more flexible. As an example, wide-band, wide-angle CPGMs with zero and non-zero phase gradient based on Pancharatnam-Berry (PB) phase are achieved using the co-polarization reflection unit cells under circularly polarized (CP) wave incidence. Both theoretically calculated and numerically simulated scattering patterns of the designed CPGMs demonstrate the expected manipulations. Additionally, two kinds of random CPGMs with different phase gradients are designed for radar cross section (RCS) reduction, and the measured RCS reveals a good accordance with the simulation.

Convolution operations on time-domain digital coding metasurface for beam manipulations of harmonics

“…(4) and (5). Hence, once the delay time t 0 = 0 and T/2 are introduced, stable anti-phase states (phase differences equal to kπ, k = ± 1, ±3 …) can be precisely obtained for all odd-order harmonics with the same amplitude, and this can be used to restrain the radiations of harmonics according to the diffusion theory [10,11,14].…”

“…For a 2-bit space-domain digital coding metasurface, digital particles turn into "00", "01", "10", and "11", whose reflection responses are characterized by four phase states of 0°, 90°, 180°, and 270°, respectively. Various functions such as random diffusions [10,11] and anomalous beam reflections/transmissions [12,13] have been realized by appropriately designing the coding profiles.…”

Printed Frequency Scanning Antenna Array With Wide Scanning Angle Range

“…Searching a low-cost means to measure the distance and angle of targets is always a great challenge in the commercial radar sensors researches [1][2][3][11][12][13][14][15][16][17][18]. In recent years, with the attractive advantages such as low profile, compact structure, wide frequency band, frequency beam scanning characteristics and easiness of integration with planar circuits, scientists and researchers have paid much attention to planar leaky-wave antennas (LWAs) [2][3][4][5][6][7][8][9][10].…”

Metasurface base on uneven layered fractal elements for ultra-wideband RCS reduction

“…In addition, Ref. 15 proposed a coding phase gradient metasurface (CPGM) made of the N-shape metallic pattern, which could come true 10 dB RCS reduction in frequency bands of 7.8-13.5 GHz with a radio bandwidth of 1.95:1. To meet the needs of engineering applications, it is highly desirable to design a metasurface for reducing monostatic and bistatic RCS of the object over an ultra-wide frequency band.…”