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1 – 2 of 2Serap Kiriş and Muharrem Karaaslan
The purpose of this study is to design a radio altimeter antenna whose production process is facilitated and can work with multiple-input multiple-output (MIMO) properties to…
Abstract
Purpose
The purpose of this study is to design a radio altimeter antenna whose production process is facilitated and can work with multiple-input multiple-output (MIMO) properties to provide space gain on the aircraft.
Design/methodology/approach
To create an easy-to-produce MIMO, a two-storied structure consisting of a reflector and a top antenna was designed. The dimensions of the reflector were prevented to get smaller to supply easy production. The unit cell nearly with the same dimensions of a lower frequency was protected through the original cell design. The co-planar structure with the use of a via connection was modified and a structure was achieved with no need to via for easy production, too. Finally, the antennas were placed side by side and the distance between them was optimized to achieve a MIMO operation.
Findings
As a result, an easy-to-produce, compact and successful radio altimeter antenna was obtained with high antenna parameters such as 10.14 dBi gain and 10.55 dBi directivity, and the conical pattern along with proper MIMO features, through original reflector surface and top antenna system.
Originality/value
Since radio altimeter antennas require high radiation properties, the microstrip antenna structure is generally used in literature. This paper contributes by presenting the radio altimeter application with antenna-reflective structure participation. The technical solutions were developed during the design, focusing on an easy manufacturing process for both the reflective surface and the upper antenna. Also, the combination of International Telecommunication Union’s recommended features that require high antenna properties was achieved, which is challenging to reach. In addition, by operating the antenna as a successful MIMO, two goals of easy production and space gain on aircraft have been attained at the same time.
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Goutam Kumar Jana, Sumit Bera, Ribhu Maity, Tithi Maity, Arjun Mahato, Shibayan Roy, Hemakesh Mohapatra and Bidhan Chandra Samanta
The manufacture of polymer composites with a lower environmental footprint requires incorporation of sustainably sourced components. In addition, the incorporation of novel…
Abstract
Purpose
The manufacture of polymer composites with a lower environmental footprint requires incorporation of sustainably sourced components. In addition, the incorporation of novel components should not compromise the material properties. The purpose of this paper is to demonstrate the use of a synthetic amine functional toluidine acetaldehyde condensate (AFTAC) as a modifier for fiber-reinforced epoxy composites. One of the fiber components was sourced from agricultural byproducts, and glass fiber was used as the fiber component for comparison.
Design/methodology/approach
The AFTAC condensate was synthesized via an acid-catalyzed reaction between o-toluidine and acetaldehyde. To demonstrate its efficacy as a toughening agent for diglycidyl ether bisphenol A resin composites and for the comparison of reinforcing materials of interest, composites were fabricated using a natural fiber (mat stick) and a synthetic glass fiber as the reinforcing material. A matched metal die technique was used to fabricate the composites. Composites were prepared and their mechanical and thermal properties were evaluated.
Findings
The inclusion of AFTAC led to an improvement in the mechanical strengths of these composites without any significant deterioration of the thermal stability. It was also observed that the fracture strengths for mat stick fiber-reinforced composites were lower than that of glass fiber-reinforced composites.
Originality/value
To the best of the authors’ knowledge, the use of the AFTAC modifier as well as incorporation of mat stick fibers in epoxy composites has not been demonstrated previously.
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