Effects of antireflective coatings on scanning performance of millimetre‐wave lenses

Sönmez, Nurdan; Tokan, Nurhan Türker

doi:10.1049/iet-map.2016.0040

Cited by 6 publications

(4 citation statements)

References 22 publications

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“…Suppose one or more matching dielectric layers are coated on the lens. In that case, the above-said effects will be reduced significantly, and it is proved with a 77-GHz hemi-spherical lens made of alumina coated with various types of anti-reflective layers (corrugations, quarter-wave, and multiple layer transformers) [31].…”

Section: Low-profile 77-ghz Antennas and Arraysmentioning

confidence: 97%

Perspectives of Convertors and Communication Aspects in Automated Vehicles, Part 2: Printed Antennas and Sensors for Automotive Radars

et al. 2021

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Automated vehicles are becoming popular across the communities of e-transportation across the globe. Hybrid electric vehicles and autonomous vehicles have been subjected to critical research for decades. The research outcomes pertinent to this topic in the literature have been motivated by the industry and researchers to emphasize automated vehicles. Part 1 of this survey addressed the critical aspects that concern the bidirectional converter topologies and condition monitoring activities. In the present part, 24- and 77-GHz low-profile printed antennas are studied for automotive radar applications. These antennas are mounted on automated vehicles to avoid collision and are used for radio tracking applications. The present paper states the types of antenna structures, feed mechanisms, dielectric material requirements, design techniques, performance parameters, and challenges at 24- and 77-GHz resonating frequency applications. The recent developments in feed methodologies, beam scanning concepts, and the effect of sidelobe levels are addressed. Furthermore, the reasons behind the transition from 24 to 77 GHz are reported in detail. The recent advances in the application of various sensor schemes in an automated vehicle have also been discussed.

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Section: Low-profile 77-ghz Antennas and Arraysmentioning

confidence: 97%

Perspectives of Convertors and Communication Aspects in Automated Vehicles, Part 2: Printed Antennas and Sensors for Automotive Radars

et al. 2021

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“…When dealing with dense dielectric materials, internal resonances are excited within the lens, resulting in gain reduction, beam distortions and increase of side lobes as well as significant deterioration of the input impedance of each radiating element [19]. The most common way to considerably minimize these undesirable effects for narrowband applications is coating the top of the antenna with quarter-wave dielectric layer [8].…”

Section: Perforated Lwa Array Designmentioning

confidence: 99%

“…Placing linear or circular corrugations on the open end of lens surface can be a reasonable solution to significantly reduce these undesirable internal reflection effects [21]. Strong internal reflections can also be minimized using wave transformers made of homogeneous [19] or artificial [22] dielectrics at the top of the lens antenna. In this work, a perforated structure is designed by drilling periodic holes in the dielectric slab to create regions of equivalently lower dielectric constants.…”

Section: Perforated Lwa Array Designmentioning

confidence: 99%

A novel planar, broadband, high gain lateral wave antenna array for body scanning applications

Tokan

Cavallo

Neto

2020

Journal of Electrical Engineering

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Three-dimensional body scanning systems are increasingly used in sensitive public areas such as airports. By providing a high resolution image of a person from all sides, it is possible to detect potential metallic, ceramic and explosive threats. For these systems, it is essential to design broadband antennas with a fan beam, highly directional radiation in one plane and wide in the other plane, and characterized by phase center stability as a function of frequency. In this paper, the planar lateral wave antenna (LWA) array is proposed to achieve these radiation requirements. The LWA has two critical shortcomings: the flaring part and the dielectric matching layers (MLs), to operate over very broad frequency bands. In this work, these shortcomings are overcomed by forming a connected array of planar LWAs to improve broadband performance and by applying necessary perforations on the dense dielectric lens antenna to create different effective relative permittivity regions. An eight element connected and perforated LWA array is designed to operate in the 8–24 GHz frequency band. The drilled holes are proved to play a similar critical role of MLs in internal reflection suppression. The results emphasize all crucial demands for body scanning systems.

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“…Strong internal reflections inside the antenna cause degradation in return loss, radiation efficiency, and gain [7,8]. These undesirable reflections can be significantly reduced by placing circular corrugations on the lens outer surface using stereolithography [9][10][11]. Stereolithography is a high-cost high-resolution additive manufacturing (AM) technique for millimeter-wave applications [12].…”

Section: Introductionmentioning

confidence: 99%

Influence of 3d Printing Process Parameters on the Radiation Characteristics of Dense Dielectric Lens Antennas

Tokan¹,

Demi̇r²,

Çalışkan³

2021

PIER C

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In recent years, additive manufacturing has found increasing interest in the fabrication of dielectric antennas. Using additive manufacturing brings significant advantages such as design flexibility, compactness, fast and low-cost manufacturing compared to traditional fabrication methods. Dielectric antennas having dense material allow high power transfer efficiency through the lens. However, a successful 3D printing process with dense dielectric materials is a great challenge. This paper investigates the impact of main process parameters during 3D printing; namely printing speed, process temperature, and layer height on the resulted relative electrical permittivity values of dense dielectric materials. Test samples are printed with a dielectric material having ε r = 10, and relative permittivity variations of these samples are measured with a vector network analyzer in . In this way, optimum printing parameters are determined. The influence of dielectric constants of printed materials on the antenna radiation characteristics is inspected for an extended hemispherical lens antenna by a fullwave computer-aided design tool. Results demonstrate that an additively manufactured dense dielectric antenna will act as a traditionally manufactured dielectric antenna if and only if it is manufactured with optimum printing parameters.

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Effects of antireflective coatings on scanning performance of millimetre‐wave lenses

Cited by 6 publications

References 22 publications

Perspectives of Convertors and Communication Aspects in Automated Vehicles, Part 2: Printed Antennas and Sensors for Automotive Radars

Perspectives of Convertors and Communication Aspects in Automated Vehicles, Part 2: Printed Antennas and Sensors for Automotive Radars

A novel planar, broadband, high gain lateral wave antenna array for body scanning applications

Influence of 3d Printing Process Parameters on the Radiation Characteristics of Dense Dielectric Lens Antennas

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