Ultra-wideband linear-to-circular polarization conversion metasurface*

Abstract

An ultra-wideband and high-efficiency reflective linear-to-circular polarization conversion metasurface is proposed. The proposed metasurface is composed of a square array of a corner-truncated square patch printed on grounded dielectric substrate and covered with a dielectric layer, which is an orthotropic anisotropic structure with a pair of mutually perpendicular symmetric axes u and v along the directions with the tilt angles of ±45° with respect to the vertical y axis. When the u- and v-polarized waves are incident on the proposed metasurface, the phase difference between the two reflection coefficients is close to –90° in an ultra-wide frequency band, so it can realize high-efficiency and ultra-wideband LTC polarization conversion under both x- and y-polarized incidences in this band. The proposed polarization conversion metasurface is simulated and measured. Both the simulated and measured results show that the axial ratio (AR) of the reflected wave is kept below 3 dB in the ultra-wide frequency band of 5.87 GHz–21.13 GHz, which is corresponding to a relative bandwidth of 113%; moreover, the polarization conversion rate (PCR) can be kept larger than 99% in a frequency range of 8.08 GHz–20.92 GHz.

Wavefront-controllable all-silicon terahertz meta-polarizer

“…Electromagnetic metasurfaces with polarization manipulations have developed from polarization conversion metasurfaces (PCMs) to meta-polarizers [1-8]. Among them, PCMs can only serve the conversion between specific polarizations [9][10][11][12][13][14][15]. Hence, an additional polarizer is generally required to obtain a certain input polarization.…”

Novel broadband angular stable linear‐circular and linear‐cross polarizer based on inductive grid loaded H‐dipole in both reflection and transmission modes

“…Lin et al introduced an ultrawideband (UWB) corner truncated square patch linear-to-circular metasurface polarizer with Axial Ratio (AR) ≤3 dB bandwidth performance from 5.87 to 21.13 GHz having 113% fractional bandwidth (FBW). 14 Zheng et al proposed a wideband linear-cross and linear-circular reflective polarizer metasurface for C to Ku-band applications. 15 The simple meanderline unitcell, in addition to a dipole, converts the linear polarized wave to its orthogonal and circular in lower and higher bands, respectively.…”

“…In addition to that, the proposed structure maintains handedness for the circular polarization, which is prominent in several applications since the circular polarization changes the handedness once it hits any reflector. Lin et al introduced an ultrawideband (UWB) corner truncated square patch linear‐to‐circular metasurface polarizer with Axial Ratio (AR) ≤3 dB bandwidth performance from 5.87 to 21.13 GHz having 113% fractional bandwidth (FBW) 14 . Zheng et al proposed a wideband linear‐cross and linear‐circular reflective polarizer metasurface for C to Ku‐band applications 15 .…”

Characteristic mode analysis of wideband high-gain and low-profile metasurface antenna*

“…Microstrip patch antennas have been widely used in wireless communication, satellite communication for their excellent performances of low profile, easy conformal, and easy processing. Electromagnetic metasurface (MTS) provides the solutions to the inherent shortcomings such as low gain and narrow band, and greatly expands the performances, such as nano imaging, [1] phase modulation, [2][3][4][5] polarization conversion, [6,7] high performance, [8] etc. However, traditional MTS has limitations in application, and good MTS needs to be designed based on rich experience.…”