CARLOS ANTONIO FRANCA SARTORI
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Artigo IPEN-doc 24924 Effects on the antenna’s radiation pattern due to metamaterial-based sub-wavelength insulation2017 - ALMEIDA, JORGE V. de; SIQUEIRA, GLAUCIO L.; MOSSO, MARBEY M.; SARTORI, CARLOS A.F.A metamaterial-based insulator is proposed for highly compact MIMO-systems. In previous work, the proposed insulator has been demonstrated to reduce efficiently the coupling at PEC boundaries between two very close antennas on a common ground plane. The present study concentrates on the effects of this insulator on the antenna radiation pattern. The chosen operating frequency is 2.4 GHz considering that it is a usual frequency for many indoor wireless applications. The theoretical results are supported by numerical simulations.Artigo IPEN-doc 24716 A hybrid approach for assessments of equivalent emission sources and electromagnetic environments2018 - CARDIA, D.V.F.; SARTORI, C.A.F.; MUYLAERT, R.P.B.This paper presents a method for equivalent emission source determination by application of LLAs (Large Loop Antennas). A review of different types of LLAs is carried out and their characteristics regarding emission source evaluation are emphasized. A hybrid technic is applied for obtaining the electric fields based on previous measurement of magnetic fields combined with an analytical and numerical approach. This methodology is proposed as an alternative to face the constraints concerning to the near electric fields measurements and calculations.Artigo IPEN-doc 22683 Metamaterial-enhanced coupling seen as non-Foster impedance matching2016 - ALMEIDA, JORGE V. de; SIQUEIRA, GLAUCIO L.; MOSSO, MARBEY M.; MAIA, MARCO A.G.M.; SARTORI, CARLOS A.F.Electrically small antennas (ESA) are characterized by high-Q impedances presenting high reactance and low radiation resistance. Since in most wireless power transmission (WPT) applications, such as inductive power transmission (IPT), to use a full-size antenna is neither practical or desired, the system overall efficiency is usually very poor due to the drivers large reactance. In the last decade, various works have demonstrated that a class of artificial material called metamaterials (MTMs) can synthesize munegative (MNG) media capable of evanescent-wave focusing which largely enhances the coupling between ESA. In the present work, MTM-enhanced coupling in IPT systems is examined. Adopting a lumped element approach to describe the general MTM-enhanced IPT system, it is evidenced that MNG media can be interpreted as a negative inductance (a non-Foster reactance) from a circuital point of view. This paper also presents an approach based on energy density to calculate the module of the MNG slab equivalent inductor.Resumo IPEN-doc 20698 Nondestructive testing in electrical devices using loop antennas2014 - MUYLAERT, RAFAEL P.B.; SEVEGNANI, FRANCISCO X.; SARTORI, CARLOS A.Resumo IPEN-doc 20615 A comparative study of large loop antennas regarding the evaluation of equivalent radiation sources2014 - CARDIA, DANIEL V.F.; SEKO, MURILO H.; SARTORI, CARLOS A.F.; BARBIN, SILVIO E.