An Equivalent Circuit/System by Design Approach to the Design of Reflection-Type Dual-Band Circular Polarizers

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%

“…As well as single band and broadband polarization converters, dual-band polarization converters have also been heavily investigated [33][34][35][36]. Fartookzadeh et al [33] introduced a dual-band circular polarization converter based on anisotropic impedance surfaces.…”

Section: Introductionmentioning

confidence: 99%

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

Zhu

et al. 2022

Sensors

“…With this approach, the converter and the antenna can be designed independently, thereby avoiding a complicated feeding network typically used in classical CP antennas. Planar polarizers can be divided into two categories: reflection-type circular polarizers [ 5 , 6 , 7 , 8 ] and transmission-type circular polarizers [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. The transmission-type circular polarizers are more common and have been widely investigated in the literature.…”

Section: Introductionmentioning

confidence: 99%

Dual-Frequency Linear-to-Circular Polarization Converter for Ka-Band Applications

Greco

Arnieri

2022

Sensors

Self Cite

A dual-band linear-to-circular planar polarization converter based on a multilayer printed circuit board (PCB) is proposed and demonstrated. Each cell of the periodic surface is formed by six substrate layers separated by five foam spacers. The three top layers are identical and contain an ‘I’-type strip, while the three layers on the bottom side are realized with three identical Jerusalem crosses (JC). A linearly polarized (LP) wave tilted 45° relative to the x- and y-axis of the converter is used to illuminate the polarizer. In this configuration, right-handed circularly polarized (RHCP) waves are generated at the Ka-band while left-handed circularly polarized (LHCP) waves are generated at the K-band. An equivalent circuit model based on transmission lines is proposed and used to design the polarizer together with full-wave simulations. The simulated/measured axial ratio (AR) remains below 3 dB in the bands 19.4–21.8 GHz (12.5%) and 27.9–30.5 GHz (8.7%) with an insertion loss better than 0.5 dB.

“…Based on the "interactive collaboration" between EAs and LBE methods, effective and efficient techniques for the synthesis of EM devices have been recently proposed according to the socalled System-by-Design (SbD) paradigm, which is defined as the "task-oriented design, definition, and integration of system components to yield EM devices with user-desired performance having the minimum costs, the maximum scalability, and suitable reconfigurability properties" [38]. The potential and the flexibility of such an approach have been demonstrated in the design of a plethora of devices including wide-angle impedance layers (WAIMs) [39], metamaterial lenses [40], holographic EM skins [41], polarizers [42], nano-structures [12], reflectarrays [43],…”

Section: Introductionmentioning

confidence: 99%

Multi-Objective System-by-Design for mm-Wave Automotive Radar Antennas

Rosatti¹,

Salucci²,

L.³

et al. 2022

Preprint

Self Cite

The computationally-efficient solution of multi-objective optimization problems (MOPs) arising in the design of modern electromagnetic (EM) microwave devices is addressed. Towards this end, a novel System-by-Design (SbD) method is developed to effectively explore the solution space and to provide the decision maker with a set of optimal trade-off solutions minimizing multiple and (generally) contrasting objectives. The proposed MO-SbD method proves a high computational efficiency, with a remarkable time saving with respect to a competitive state-of-the-art MOP solution strategy, thanks to the "smart" integration of evolutionary-inspired concepts and operators with artificial intelligence (AI) and machine learning (ML) techniques. Representative numerical results are reported to provide the interested users with useful insights and guidelines on the proposed optimization method as well as to assess its effectiveness in designing mm-wave automotive radar antennas.