88 research outputs found
Spectral properties of signal fading and Doppler spectra distribution in urban mobile communication links
Diffusion spreading of middle-latitude ionospheric plasma irregularities
In contrast to the way that the spreading of
irregularities in a plasma is usually considered, the diffusion spreading of
irregularities stretched along the geomagnetic field B is
examined using a three-dimensional rigorous numerical model of quasi-neutral
diffusion in the presence of a magnetic field, in conjunction with the actual
height variations of the diffusion and conductivity tensors in the ionosphere. A
comparison with the earlier constructed approximate model of unipolar diffusion
was made. As in the previous case, the same peculiarities of irregularity
spreading in the inhomogeneous background ionospheric plasma were observed. The
accuracy of the approximate model for describing the process of spreading of
anisotropic ionospheric irregularities is established. Time relaxation effects
of real heating-induced ionospheric irregularities on their scale transverse to B
are presented using the approximate analytical model for the case of a
quasi-homogeneous ionospheric plasma. The calculated results have a vivid
physical meaning and can be directly compared with experimental data on the
radiophysical observations of artificial heating-induced irregularities created
by powerful radio waves in the ionosphere
Diffusion spreading of middle-latitude ionospheric plasma irregularities
In contrast to the way that the spreading of irregularities in a plasma is usually considered, the diffusion spreading of irregularities stretched along the geomagnetic field <strong>B</strong> is examined using a three-dimensional rigorous numerical model of quasi-neutral diffusion in the presence of a magnetic field, in conjunction with the actual height variations of the diffusion and conductivity tensors in the ionosphere. A comparison with the earlier constructed approximate model of unipolar diffusion was made. As in the previous case, the same peculiarities of irregularity spreading in the inhomogeneous background ionospheric plasma were observed. The accuracy of the approximate model for describing the process of spreading of anisotropic ionospheric irregularities is established. Time relaxation effects of real heating-induced ionospheric irregularities on their scale transverse to <strong>B</strong> are presented using the approximate analytical model for the case of a quasi-homogeneous ionospheric plasma. The calculated results have a vivid physical meaning and can be directly compared with experimental data on the radiophysical observations of artificial heating-induced irregularities created by powerful radio waves in the ionosphere
Radio propagation and adaptive antennas for wireless communication networks
Explores novel wireless networks beyond 3G, and advanced 4G technologies, such as MIMO, via propagation phenomena and the fundamentals of adapted antenna usage.Explains how adaptive antennas can improve GoS and QoS for any wireless channel, with specific examples and applications in land, aircraft and satellite communications.Introduces new stochastic approach based on several multi-parametric models describing various terrestrial scenarios, which have been experimentally verified in different environmental conditionsNew chapters on fundamentals of wireless networks, cellular and non-cellular
Radiophysical and geomagnetic effects of rocket burn and launch in the near-the-earth environment
Radiophysical and Geomagnetic Effects of Rocket Burn and Launch in the Near-the-Earth Environment describes experimental and theoretical studies on the effects of rocket burns and launchings on the near-the-Earth environment and geomagnetic fields. It illuminates the main geophysical and radiophysical effects on the ionosphere and magnetosphere surrounding the Earth that accompany rocket or cosmic apparatus burns and launchings from 1,000 to 10,000 kilometers.The book analyzes the disturbances of plasma and the ambient magnetic and electric fields in the near-Earth environment from rocket bur
Circularly polarized defected ground stubâmatched tripleâband microstrip antenna for Câ and Xâband applications
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