Buscar recursos académicos

Abstract This paper presents a radiopropagation algorithm based on a Ray Tracing (RT) technique that combines a modified multipath model for constant refractivity gradient profiles and the Uniform Theory of Diffraction (...

Abstract The growing demand for multiparameter sensors includes compact devices accompanied by simple calibration processes to distinguish the outputs from each other. This paper evaluates a scheme to determine multiple ...

Abstract This paper describes an investigation of the possibility of using a new conductive ink, insted of copper clad laminates, in the manufacturing of microstrip patch antennas on glass and fiberglass substrates and o...

Abstract Recently research show that some parameters such as the shapes of antenna patch and the ground plane when geometrically altered produces changes in the current density distribution of the planar structure and co...

Abstract In this paper a 2-4 GHz microstrip IFM (Instantaneous Frequency Measurement) subsystem that uses Wilkinson power dividers, frequency discriminators based on band-stop filters and a DC arduino section is reported...

Abstract In this work a broadband Magnetoelectric (ME) dipole antenna for the Global Navigation Satellite System (GNSS) applied to nanosatellites is proposed. The antenna consists of a reflective cavity with open walls c...

Abstract This paper originates from a practical experiment based on Mesh Networks. The promising results obtained from this experiment prompted us to discuss in greater depth whether Wireless Local Area Networks (WLAN) a...

Abstract In this article, a small Quad-Band microstrip patch antenna with folded strip lines for WiMAX/WLAN and ITU Applications is presented. This antenna consists eight symmetrical rectangular folded strip lines with 2...

Abstract The presented model for wideband circularly polarized microstrip antenna is an improved version of the previous models which is widely applicable to satellite, microwave relay and radar. The designed circularly ...

In this paper a three layer FSS is described which provides a ultrawide band (UWB) response. The layers use plain rectangular patches, and rectangular patches with one or two notches which provide multi-band responses; b...

This paper shows fundamentals and results that support a promising methodology for evaluation in locus of a LED from its own radiating signal, and that allows monitoring of its aging by remote inference on which degradat...

Abstract This paper presents a reflectarray antenna with an innovative dielectric mirror in the form of a discretized concave reflector. The mirror, manufactured via 3D printing, combines dielectric and air layers, formi...

Abstract Frequency Selective Surfaces (FSS) are increasingly being used in telecommunications systems due to the numerous advantages presented by this sort of structure, among them low cost, ease of fabrication, and low ...

Abstract An accurate modeling of materials is essential to obtain reliable results in fields calculation. The Jiles-Atherton approach is widely used for modeling the magnetic hysteresis and depends on its set of five par...

Abstract This paper presents the optimization performance of non-uniform linear antenna array with optimized inter-element spacing and excitation amplitude using Particle Swarm Optimization (PSO). The aim of the proposed...

In this paper a truncated corner rectangular microstrip antenna (TCRMA) is analyzed in the presence of carbon fiber composite (CFC) material. Simplified carbon fiber composite models are proposed and the analyses are per...

Abstract We use the two dimensional finite element method (2D-FEM) in the frequency domain to characterize the transmission properties of 90°-bend periodic segmented waveguides (PSWs). We investigated the dependence of ...

Abstract We investigate an analytical approach based on transmission line model to design mantle cloak for multilayer and/or inhomogeneous dielectric objects. Our proposed model is verified with different numerical resul...

Abstract In this work a Finite-Difference Frequency-Domain (FDFD) propagation method for complex urban environments is proposed. The formulation starts from the discretization of the Helmholtz equation for the magnetic f...

Abstract The physical topology design (PTD) of optical networks is frequently accomplished by combining several solutions in an iterative way, especially if meta-heuristics are deployed for this purpose. Suitable operato...

Abstract The systemic behavior of a Semiconductor Optical Amplifier model was optimized through extensive simulations, reaching reasonable approximation to experimental obtained from commercial devices for the optical ga...

Abstract This paper presents the propagation channel characteristics of a digital TV single-frequency network (SFN) obtained by carrying out field measurements using two synchronized transmitters. The measurements are pe...

Abstract The Internet of Things (IoT) encompasses a diverse array of solutions with applications ranging from smart cities to environmental monitoring and industrial processes. In this context, communication techniques t...

Abstract The rapid development of the Fifth Generation (5G) networks encourages researchers to improve the Radio over Fiber (RoF) technique to achieve data rates of 10 Gbps and beyond. That led to a significant increase ...