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Overview of the drivers and key enabling technologies for 5G mm-wave wireless communication systems will be given. Innovative mm-wave antenna designs, such as holographic antennas and metamaterial flat lens antennas will be presented.
The aim of this paper was the efficiency improvement of methods for measurement of electric field strength in the vicinity of base stations, which was achieved in two areas: procedure for using shorter time intervals of averaging (comparing to 6min that standards stipulate) and model for the conversion from mono-axial measurements to isotropic case.
This paper presents one solution of EPG (Electronic Program Guide) data propagation in DTV set-top box. Propagation is based on a existing solution and extensive process optimization has been done. Optimization reflects in lesser memory consumption and in lesser time consumption in propagating EPG data in contrary to the original state. The result is faster access to the requested data and faster...
This research aims to gain insight into evaluation methodology and to contribute to a higher standard of Web-based GIS applications evaluation in practice. We explored existing usability standards and published usability models to determining an appropriate model for evaluating the usability of WebGIS. The main goal of this study is to propose a comprehensive methodology for usability evaluation and...
The key indicator of telephone connection setup speed is Post Selection Delay (PSD). The analysis of PSD in telephone networks and its characteristics is performed. Due to differences in transmission of address information in classic and new telephone networks, conditions dealing with the PSD are not same. This conclusion is formulated in the proposition for changing existing target values related...
As the effects of global warming are spreading globally, the world population encounters one of the most important social and scientific phenomena-changing the parameters of the environment due to pollution. Any conducted action requires precise and accurate measuring of the environmental parameters at several dozens of thousands points deployed around the world. Since financially, as well as practically,...
LPDA (Log Periodic Dipole Arrays) as a reflector antenna feed offers wide range for applications. However, phase center of the LPDA changes depending on the operation frequency, which, in turn, leads to defocusing loss as frequency changes. In this study, design of 1–18 GHz printed LPDA antenna is used as a linearly polarized feed for the parabolic reflector which has a 1.2 m diameter. Optimal feed...
This paper introduces the Neuroevolution of Augmenting Topologies method for evolving artificial neural networks to play game 2048. Over the course of several hundred generations, the network evolves and learns how to play game.
Wideband, high gain and low profile aperture coupled antenna for SatCom applications is proposed and designed. The antenna operates over the entire Ku band spectrum of SatCom, which starts from 10.5 GHz to 14.5 GHz. Thus, the antenna can be used reception and transmission at the same time. Apart from gain, bandwidth and HPBW, other features such as front to back ratio, inband gain ripple, electrical...
We propose a low-cost solution for jamming mitigation of GPS by electronically switching antenna beam. Jamming signals are assumed to be directed from low elevation angles so that antenna rejection from zenith to low elevation must be improved by switching from wide angle half power beam width to a narrow one. Using low-cost, commercially available ceramic patches, four-element antenna array and its...
This paper deals with the problem of designing a Microwave biological reactor operating in resonance conditions at 915 MHz. Though resonant cavities are well-known electromagnetic devices, when the irradiation phenomena occur in presence of chemical or biochemical systems, e.g. aqueous solutions, most of the design equations lose their meaning and, hence, should be modified. Thus, a general approach...
Electromagnetic scattering of a point electric current source radiating in the vicinity of a PEC wedge which resides in lossy medium is studied. Dyadic Green's functions for longitudinal components are derived and paraxial field representations are obtained. At the end of the analysis, asymptotic forms of the dyadic Green's functions are presented.
In the recent years the demand for real time video delivery has been increased. Hence, real time video distributers must ensure that the end-user quality-of-service is met (QoS). There are multiple conditions which can have influence on the transmission of video content, such as type of transmission, channel capacity, data loss, coding etc. Data loss mostly occurs in packet switched networks. This...
An expression of correlation function of channel coefficients when one-ring scattering model is derived. Based on the correlation function a recursive model of channel coefficients is obtained. A nonrecursive algorithm of channel filtration is derived with Wiener filtration theory.
Wide band digitally controlled attenuator implemented in standard 130nm UMC CMOS process has been presented. Attenuator is composed of four cascade Pi-attenuation cells, and it is designed to achieve constant attenuation step size in a wide frequency range from 3.2 to 9.3 GHz.
A significant linearity improvement of the power amplifier (PA) performance designed for and subjected to dynamic gate bias operation, is shown in a comprehensive computer simulation. Simulation was based on a data measured with a time domain measurement technique. A dynamic gate biasing technique was used to keep the phase of the PA flat until PA reaches deep compression level in order to reduce...
This paper presents investigation on how linearity performance changes for different gate bias voltages for the ET and AET 10 W GaN HEMT power amplifier. It is shown that by selecting optimal gate bias voltage, AM-AM and AM-PM transfer characteristics can be more constant for a given power dynamic range which results with better linearity. Moreover, the efficiency can stay preserved. Benefit of selecting...
A light field camera captures intensity and direction information of the light rays entering the main lens of the camera. Novel applications based on light field technologies are currently under development. Among the several research challenges, such as compression and transmission, another important issue is related to the quality evaluation of views rendered from light field data. This paper discussed...
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