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The present paper focuses on TCS21 achieved results, which have not been published so far and that are fully consistent with CDR predictions. A synthesis of study main achievements is presented.
In this paper we introduce a new methodology to design beam-forming networks - BFN for phased arrays systems, in which, to scan the beam, is not longer necessary to use a phase shifter for each radiating element conforming the array. The new methodology is based in the coherently periodic radiating structures (CORPS) principles. With the use of this concepts, we can reduce the electronic necessary...
The aim of the paper is models development and experimental validation of millimeter waves narrow beam propagation in shadow zone of the urban building. Establishment dependence of interference fading from parameters for a narrow beam, height of antennae, distance between antennas by propagation above terrestrial cover in rural conditions.
The satellite propagation systems are affected by the presence of precipitation in the path of propagation to a great extent Thus, for the optimum performance of a communication link, the system designer needs to have the knowledge about the slant path attenuation prediction for which effective rain height is an important parameter. Here we present the results of the Effective rain height in statistical...
More and more applications require small conformal ultra-wide bandwidth (UWB) antenna designs. The radiation performance of such antennas faces fundamental limitations imposing on impedance, gain and bandwidth. Antenna miniaturization can be achieved by slowing down the currents and fields propagating along antenna arms. Convention approaches involve the utilization of dielectric loading or meandered...
In this paper the Koch fractal antenna at UHF frequency will be analyzed. In particular, a new technique proposed to adapt the input impedance of the Koch model to be matching with the impedance of the RFID chip. It is important to remark that the proposed technique conserves the same special form of the bi-band Koch dipole model. The Bi-band fractal antenna with input impedance 50 ohms is compared...
In this paper we are focusing on the practical, engineering way of evaluating and characterizing the multi-channel antenna solutions on the mobile terminal. Two methods of calculating the parameters, describing the diversity performance, are described and the practical use of the methods in simulations and measurements are presented and evaluated. The time saving aspect of using the scattering parameters...
A generic numerical tool has been developed to compute/optimize the sensitivity of array antenna receiver systems. This antenna system simulator is comprised of an ElectroMagnetic (EM) simulator and a MicroWave simulator (MW) for modeling the signal and noise characteristics of each receiver component. This analysis includes accurate modeling of the background noise (sky+ground), which is essential...
The outage performance of broadband fixed satellite links operating above 10GHz is predominantly controlled by rain attenuation. The purpose of this paper is the presentation of a general physical model for the prediction of the outage statistics and error performance of a dual polarized satellite link using Weibull distribution. The obtained numerical results focus on the investigation of the effects...
The paper presents investigations into compact zero-thickness wideband antennas capable of operating in many frequency bands within 800-3000 MHz. Multi-band operation of these antennas is accomplished by suitable meandering of conducting segments that may be supported by a thin dielectric film. The antennas are capable of operating with a very small ground plane formed by an adjacent conducting surface...
A compact triangular monopole antenna fed by a tapered-coplanar waveguide (CPW) is presented. The simulated and measured return loss results are presented. The proposed antenna offers a wide bandwidth from 4.14??9.84 GHz (81%) covering WLAN frequency bands for IEEE 802.11a and HiperLAN2 as is seen from the measured results.
This paper describes a novel type of miniature microstrip patch antenna based on fractal geometry. Miniature properties are achieved by the presence of unusual fundamental resonant mode which we call "crossed-diagonal" (CD) current.
It has recently been shown that a coupled impedance network is required to maximize the power received by a coupled array for arbitrary incident field. This paper explores the performance of uncoupled terminations under different incident field assumptions. The analysis shows that under certain impinging fields, an uncoupled load can be designed whose performance matches that of the optimal termination...
Electromagnetic bandgap structures (EBG) finds increasing number of applications in antennas and microwave devices. In this paper, we present an EBG resonator antenna based on woodpile structure at millimeter frequency. The dispersion characteristics of the woodpile structures have been analyzed using 3D FDTD codes with a periodic boundary condition (PBC). An annular slot antenna is used as the radiating...
Based on rain gauge and radar measurements this paper discusses the variability of the spatial distribution of precipitation in the Amazon region. Regarding the horizontal behaviour, the emphasis is given to the dimension and statistical characteristics of rain cells. On the other hand, the problem associated to the vertical extent of rain is stressed with a few examples for different types of precipitation...
A complete wideband radio channel sounding campaign performed at 38.95 GHz is presented in this paper. A sounder based on correlation of pseudorandom maximal length sequences has been used, but introducing some novelties in the classical scheme of this kind of sounders. Different antenna pattern and polarization have been combined with three groups of environments, indoor, outdoor and indoor-outdoor,...
This paper deals with geometric parameters analyzing of unequidistant antenna array with irregular amplitude distribution on its working frequencies. As criterion of optimization, the overlapping coefficient of effective range of frequencies was selected.
As wearable electronic devices continue to become popularized, there is an increasing demand for these components to provide the capability of exchanging data wireless with high capacity. Currently, there is strong motivation for the development of body-centric link networks. The efficiency of these networks relies heavily on the propagation characteristics of radiated energy in the presence of the...
Modern electronic medical implants have reached a high degree of complexity. This has increased the demands on the communication link with the implant, both regarding the bandwidth and the communication distance. A medical communication system at RF frequencies has been standardised, the Medical Implant Communication System (MICS), which use a frequency allocation of 402 ?? 405 MHz. This frequency...
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