scholarly journals 2-D Beam Focusing Control Based on Passive Frequency Selective Surface (FSS)

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1938
Author(s):  
Jeong-Hyun Park ◽  
Jae-Gon Lee
Keyword(s):  
Design Methodology ◽  
Phase Variation ◽  
Frequency Selective Surface ◽  
The Novel ◽  
Transverse Beam ◽  
Beam Focusing ◽  
Phase Combination ◽  
Frequency Selective ◽  
Novel Design ◽  
Transmission Phase

In this paper, the novel design methodology of 2-D beam focusing control based on passive frequency selective surface (FSS) is proposed and described. The beam focusing antenna is composed of 1-D array source and 2-D FSS having a good transmittance and a full transmission phase variation of 360°. The 2-D FSS is designed to make the phase of wave radiated by one source be in-phase, so the transmission phase of the 2-D FSS is concave in itself. Then, the designed 2-D FSS is integrated to the 1-D array source and the longitudinal and the transverse beam focusing controls can be achieved by changing the phase shape of the array source. The relation between the focusing point and the phase combination of the sources is analyzed by a parabolic formula, and the performance of the beam focusing control system is confirmed by both simulation and measurement. From both results, it is concluded that the focusing spot can be tuned longitudinally and transversely by the proposed methodology at 5.8 GHz. In addition, the electric field intensity of 1-D array source with 2-D FSS increases by about 35% compared to that of only 1-D array source.

Emerald – a 16-rotor multicopter for stereo imaging

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Svetoslav Zabunov ◽  
Garo Mardirossian ◽  
Katia Strelnitski
Keyword(s):  
Design Methodology ◽  
The Novel ◽  
Stereo Imaging ◽  
Content Type ◽  
Rotor Design ◽  
Novel Concept ◽  
Novel Design ◽  
Practical Implications ◽  
Prototype Testing

Purpose The current manuscript aims to propose a novel multirotor design. Design/methodology/approach This paper presents a novel 16-rotor multicopter design named Emerald. The novel design innovations and benefits are disclosed. Comparison to existing 16-rotor designs is carried out. Implementation areas where the novel idea shall yield benefit are discussed. A prototype of the presented design is described. Findings The herein proposed 16-rotor design has a number of benefits over existing 16-rotor multicopters. The paper elaborates on those advantages. Research limitations/implications The research was limited to prototype testing, as the presented design is a novel concept. Practical implications The motivation to research and develop this novel design is implementing the vehicle for stereoscopic photography and reconnaissance. The design is also applicable to carrying payloads while flying indoors.

Investigation on moist silica sand’s circulation for sand mold printing with line-forming

2019 ◽  
Vol 25 (8) ◽  
pp. 1411-1420 ◽  
Author(s):  
Donghua Zhao ◽  
Weizhong Guo ◽  
Baibing Zhang ◽  
Feng Gao
Keyword(s):  
Design Methodology ◽  
Sand Mold ◽  
Silica Sand ◽  
The Novel ◽  
Paper Briefly ◽  
Content Type ◽  
Feeding Modes ◽  
Casting Industry ◽  
Circulation Problem ◽  
Novel Design

Purpose This paper aims to investigate the circulation of moist silica sand to provide appropriate feeding modes and references for designing the coating device when printing sand mold with line-forming. Design/methodology/approach First, this paper briefly introduces sand mold printing with line-forming and the circulation problem brought by moist silica sand. The outlet may be choked due to poor flowability and solidification characteristic, resulting in poor dimensional tolerance and even production failure. Then, based on circulation modeling, a series of feeding modes is proposed to guarantee adequate feeding, avoid solidification and ensure successful fabrication. Finally, the GUI of control software is developed, including slicing, path planning and the function of virtual printing. Findings Several feeding modes of moist silica sand are put forward to avoid the choke. Research limitations/implications The authors will further investigate the flowability of furan no-bake sand based on experiments. Originality/value This paper is going to provide references for the novel design of nozzle, prototype and sand mold printing, influencing significantly on mold manufacturing and the casting industry. This research applies equally to equipment having the circulation of high moist particles with solidification features.

A novel design of ultra-wide stop-band single-layer frequency selective surface using square-loop and cross

2020 ◽  
pp. 1-10
Author(s):  
Amit Birwal ◽  
Sanjeev Singh ◽  
Binod Kumar Kanaujia
Keyword(s):  
Stop Band ◽  
Single Layer ◽  
Frequency Selective Surface ◽  
Transverse Magnetic ◽  
Unit Cell ◽  
Gain Enhancement ◽  
Single Side ◽  
Frequency Selective ◽  
Novel Design ◽  
Excellent Stability

Abstract In this paper, a novel design of ultra-wide stop-band single-side single-layer frequency selective surface (FSS) is presented. The unit cell of the proposed FSS is designed using the combination of conventional square loop and cross (CSLC). To enhance the bandwidth of this structure, an additional cross is inserted in all the four quadrants of CSLC. The stop-band transmission bandwidth assuming −10 dB threshold is found to be 128.94% (2.16–10 GHz) which is 34.33% more as compared to the bandwidth of CSLC. The unit cell with a dimension of 16 × 16 mm2 is printed on one side of an FR4 substrate. The design is fabricated and the measured results are found to be in good agreement with the simulated results. The design provides excellent stability for both transverse magnetic and transverse electric polarizations. The design is very flexible, where any resonant frequency can be achieved by changing the length of unit cell. The design is useful in many applications such as antenna gain enhancement, electromagnetic wave shielding for Wi-Fi/5G systems, and other Internet of Things-based applications.

scholarly journals Bandwidth Improvement of EBG Resonator Antennas Using Double-Layer FSS

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Lina Moustafa ◽  
Bernard Jecko
Keyword(s):  
Band Gap ◽  
Double Layer ◽  
Phase Variation ◽  
Frequency Selective Surface ◽  
Electromagnetic Band Gap ◽  
Reflection Phase ◽  
Frequency Selective ◽  
5 Ghz

A double-layer frequency selective surface (FSS) is proposed as a means to enhance the bandwidth of an electromagnetic band gap (EBG) resonator antenna. Due to its inverted reflection phase variation and its wide selectivity bandwidth, the structure used in the radiating wall of the resonator allows increasing the radiating bandwidth of the last one. The resonator is fed by a patch feeding source placed inside the cavity at the proximity of its metallic ground. The antenna bandwidth is significantly improved by virtue of employing the double-layer FSS. Modelled results of an antenna working at 5 GHz are shown.

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