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Abhishek Kumar

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3 records found

Conference paper (2022) - Abhishek Kumar, Garima Jain, undefined Suraj, Prakhar Jindal, Vishwas Mishra, Shyam Akashe
These day, due to tremendous growth of wireless communication and the need for higher data transfer rates and portable and compact devices, the need for antenna with a simple design, small size, reliable radiation pattern while retaining an incredibly large frequency spectrum is on high demand. However, Ultra-Wide Band (UWB) antenna design is particularly challenging for portable devices. Nevertheless, UWB antenna design faces several challenges especially for portable devices, containing the UWB quality of impedance matching, small antenna size, constant group delay, radiation stability, and low production costs, etc., for consumer usage. Because of their low profile, broad impedance bandwidth and compact design, ease of fabrication, etc. Today, Ultra-Wide-Band antennas (UWB) have been analyzed and their features explored in the future wireless communication of the fifth generation (5G). The antennas are called planned and the scale should be minimal, so that the geometry in the 5G candidate frequency bands will be properly optimized to operate within an ultra-wide frequency band. Microstrip antenna are very successful candidates for wireless communication systems. In this research paper, by using UWB Application, we proposed a novel concept design and study of a coplanar wave guide (CPW) fed UWB for 5G. Our proposed patch antenna is elliptical in shape that offers greater degree of freedom and flexibility in design compared to circular configuration and can also provide circular polarization by proper selection of ellipse feed line while CPW-fed provides strong matching impedance. ...
Journal article (2020) - Dion J. Koeze, Lingtjien Hong, Abhishek Kumar, Brian P. Tighe
Numerous soft materials jam into an amorphous solid at a high packing fraction. This nonequilibrium phase transition is best understood in a model system where particles repel when they overlap. Recently, however, it was shown that introducing any finite amount of attraction between particles changes the universality class of the transition. The properties of this "sticky jamming"class remain almost entirely unexplored. We use molecular dynamics simulations and scaling analysis to determine the shear modulus, bulk modulus, and coordination of marginal solids close to the sticky jamming point. Each observable differs not just quantitatively but also qualitatively from the purely repulsive case. ...
While jamming is best understood in the context of purely repulsive soft spheres, emulsions and other experimental realizations of the soft sphere model commonly display weakly cohesive forces. We perform simulations of soft spheres with a finite-ranged attractive tail in the pair potential. The resulting attractive soft sphere packings can be stable at volume fractions below the purely repulsive jamming point. These new jammed states have counter-intuitive properties -- for example, while attraction introduces tensile forces, their presence leads to an increase in the compressive stress. We use critical scaling analysis to characterize the geometry and mechanics of attractive soft sphere packings as a function of both the volume fraction and the range of the attractive interaction. ...