Design and Analysis of Broadband Ultrathin Reflective Linear-to-Circular Polarization Converter Using Polygon-Based Anisotropic-Impedance Surface

Zhu

et al. 2022

Sensors

Herein a dual-band wide-angle reflective circular polarization converter, based on a metasurface was developed. The unit cell is composed of a split square ring and a nested square patch. The split square ring plays the role of creating polarization conversion. The square patch is useful for improving the quality of axial ratio. It was verified that the structure could transform the x-polarized incident wave into left-hand circular polarization in the lower frequency band, and to right-hand circular polarization in the higher frequency band. For y-polarized incidence, the transformation has orthogonal modes to that for x-polarized incidence. Moreover, the 3 dB axial ratio takes place in the ranges of 8.42–12.32 GHz and 18.74–29.73 GHz, corresponding to a relative bandwidth of 37.61%, and 45.35%, respectively. In addition, the polarization conversion efficiency is greater than 99% in the ranges of 8.65–11.83 GHz and 19.55–29.36 GHz. Furthermore, for oblique incidence, the axial ratio remains stable, even at 50° incidence, for the lower frequency band. Lastly, a prototype is fabricated and measured for experimental verification. The measured and simulated results were in good agreement. Compared with other designs in the literature, the proposed converter operates with good performance in dual-band, with high-efficiency, and with angular stability.

Section: Introductionmentioning

confidence: 99%

“…However, both designs only operated at normal incidence and narrow operational bands. Further efforts were made to broaden the bandwidth and the angular stability [31,32]. In Ref.…”

Section: Introductionmentioning

confidence: 99%

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Dual-Band Wide-Angle Reflective Circular Polarization Converter with Orthogonal Polarization Modes

Zhu

et al. 2022

Sensors

2022 16th European Conference on Antennas and Propagation (EuCAP)

“…EM metasurfaces that convert linear polarization (LP) to circular polarization (CP) and vice versa, which we will simply refer to as polarizers, have attracted significant interest, especially in the microwave regime [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. This is because circular polarization is more effective than linear polarization for establishing and maintaining mobile communication links due to their robustness to channel-induced effects from absorption, cross-polarization interference, impaired line-of-sight paths, Faraday rotation effect due to the ionosphere, and multi-path propagation.…”

Section: Introductionmentioning

confidence: 99%

“…This is because circular polarization is more effective than linear polarization for establishing and maintaining mobile communication links due to their robustness to channel-induced effects from absorption, cross-polarization interference, impaired line-of-sight paths, Faraday rotation effect due to the ionosphere, and multi-path propagation. Polarizers can operate in reflection [3][4][5][6][7][8][9]17] or transmission mode [10][11][12][13][14][15][16], where the incident linearly-polarized wave is converted to a reflected or transmitted circularly-polarized wave, respectively. The transmissive polarizers are great solutions for integration with linearly-polarized antennas; however, they are usually composed of more than one layer of scatterers and can introduce insertion loss to the converted wave.…”

Section: Introductionmentioning

confidence: 99%

Inverse Design of a Dual-Band Reflective Polarizing Surface Using Generative Machine Learning

Naseri

Goussetis

Fonseca

et al. 2022

Electromagnetic linear-to-circular polarization converters with wide-and multi-band capabilities can simplify antenna systems where circular polarization is required. Multi-band solutions are attractive in satellite communication systems, which commonly have the additional requirement that the sense of polarization is reversed between adjacent bands. However, the design of these structures using conventional ad hoc methods relies heavily on empirical methods. Here, we employ a data-driven approach integrated with a generative adversarial network to explore the design space of the polarizer meta-atom thoroughly. Dual-band and triple-band reflective polarizers with stable performance over incident angles up to and including 30 • , corresponding to typical reflector antenna system requirements, are synthesized using the proposed method. The feasibility and performance of the designed polarizer is validated through measurements of a fabricated prototype.

Dual wideband high‐efficient reflective linear‐to‐dual‐circular dual‐rotational polarization converter with two complementary twin‐split square‐ring resonators

Zaker

2024

Int J Communication

SummaryA high‐efficient linear‐to‐circular polarization (LP‐to‐CP) converter with dual‐band, dual‐rotational‐direction reflectivity using a single‐layer selective surface (FSS) with a thickness of at 3.5 GHz is designed and investigated. The unit cell, measuring 8 mm × 8 mm ( at 3.5 GHz), consists of two dual‐slotted square rings, with the outer ring providing two nonadjacent CP bands with two reflective resonances in each. The inner ring, with a 90° rotation and the ability to create different polarization and phase behavior, obtains two wide bands with high CP quality. Parametric studies and optimal results show an interesting fact that incident x(y)‐direction LP wave is effectively converted into right‐hand CP, that is, RHCP (left‐hand CP, i.e., LHCP) wave at the former band and into LHCP (RHCP) at the later band. Finally, a practical 10 × 10 optimal array is fabricated which offers excellent axial ratio below 2 dB over two wide bandwidths: 3.46 to 5.96 GHz (53%: S and C bands) and 7.8 to 12.2 GHz (44%: X band). The converter is angularly stable over 45° and 30° in the stated bands, respectively. A good agreement between simulation and measurement and essential comparisons with literature are also proposed. The results demonstrate significant potential for different dual‐band CP applications with simultaneous isolated uplink and downlink.