Produção Nacional
Revisado por pares
Francelli Klemba Coradin, Gustavo Rafael Collere Possetti, Ricardo Canute Kamikawachi, Márcia Müller, José Luís Fabris,
In this work is evaluated the performance of etched fiber Bragg gratings, assembled in different configurations to operate as a refractometric sensor, in the analysis of water-ethanol mixtures. Two fiber Bragg gratings operating close to 1300 nm and 1500 nm were wet-etched and employed in the sensor design. Four configurations for the refractometric sensor were studied, in dual-wavelength and single-wavelength operation modes, and at two sample temperatures. Calibration curves were determined for ...
Tópico(s): Photonic Crystal and Fiber Optics
2010 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Zhongbao Wang, Shaojun Fang, Shiqiang Fu,
A wideband patch antenna is proposed. By using the dual-layer patch configuration and modified L-strip feed technique, the impedance bandwidth of the patch antenna for VSWR<1.2 is broadened to 22% with respect to 900 MHz, which is superior to the other available patch antennas. In addition, by means of the modified L-shaped strip, the high cross polarization levels of the proposed antenna are suppressed effectively. Simulation results are compared with the measurements, and a good agreement is obtained. ...
Tópico(s): Microwave Engineering and Waveguides
2010 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Chengyuan Liu, Tao Jiang, Yingsong Li,
A compact CPW-fed ultra-wideband antenna with dual band-notch characteristic is presented. Two notched frequency bands are obtained by embedding two U-shaped slots in the radiation patch and a rectangle slot in the ground plane. The two notched bands can be controlled by adjusting the length of the responding slots. The proposed antenna is successfully simulated, fabricated and tested. Experimental and numerical antenna shows that the proposed antenna with compact size of 21×28mm2, has an impedance ...
Tópico(s): Wireless Body Area Networks
2011 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Blaise Ravelo, Serge De Blasi,
Recent studies proved that certain electronic active circuits are capable to exhibit simultaneously a negative group delay (NGD) and amplification in microwave frequency bands. One of the simplest topologies generating this counterintuitive NGD function effect is formed by a series RLC-network in cascade with a transistor. By using this cell, similar to the classical electronic functions, dual-band NGD microwave devices with loss compensation possibility can be designed. Theoretic demonstrations ...
Tópico(s): Photonic and Optical Devices
2011 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Ahmed Boutejdar, A.S. Omar, Edmund P. Burte, Reinhard Mikuta,
A novel compact wideband high-rejection lowpass filter (LPF) using H-DGS is presented. The proposed filter has neither open stub nor cascaded high-low impedance elements. It consists of two coupled H-slots in the ground plane along with a compensated line. The effect of the new slot on the filter performance is examined. The comparison with the conventional filters shows that the proposed one guarantees a large rejected-band of 20dB from 2.5 to 16 GHz. Experimental measurements by means of HP8719D ...
Tópico(s): Full-Duplex Wireless Communications
2011 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
B. S. L. Castro, Márcio R. Pinheiro, Gervásio P. S. Cavalcante, Igor Ruiz Gomes, Oziel de O. Carneiro,
This paper presents a performance comparison between known propagation Models through least squares tuning algorithm for 5.8 GHz frequency band. The studied environment is based on the 12 cities located in Amazon Region. After adjustments and simulations, SUI Model showed the smaller RMS error and standard deviation when compared with COST231-Hata and ECC-33 models.
Tópico(s): Power Line Communications and Noise
2011 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Raj Kumar, Prem Narayan Chaubey,
This article describes the CPW-feed ultra wideband tree type monopole fractal antenna and it’s backscattering. The prototype antenna is fabricated with optimized dimension. The experimental result of this antenna exhibits the ultra wideband characteristics from 5.0 GHz to 14.0 GHz. The experimental and simulated results are in good agreement. The effects of various design parameters on impedance bandwidth have also been studied in detail using EM simulator. The nature of H and E - plane radiation ...
Tópico(s): Microwave Engineering and Waveguides
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
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 performed by the electromagnetic simulator Computer Simulation Technologies (CST). Theoretical and experimental results of return loss, axial ratio, input impedance and radiation pattern for the antenna located on the aluminum and CFC plates are presented and compared. The results show ...
Tópico(s): Microwave Engineering and Waveguides
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Suganthi Santhanam, K. Murugesan, S. Raghavan,
This paper presents Artificial Neural Network (ANN) implementation for the Radio Frequency (RF) and Mechanical modeling of lateral RF Micro Electro Mechanical System (MEMS) series micro machined Single pole double through (SPDT) switch. We propose an efficient approach based on ANN for analyzing the losses in ON and OFF state of lateral RF MEMS series switch by calculating the S-parameters. The double beam structure has been analyzed in terms of its return, isolation and insertion losses with the variation ...
Tópico(s): Photonic and Optical Devices
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Arup Ray, Manisha Kahar, Sushanta Biswas, Debasree Sarkar, Partha Pratim Sarkar,
A single substrate layer double metallic plane frequency selective surface (FSS) is designed with miniaturized electrical elements and two tunable pass-bands enabling Wireless Local Area Network applications. Each FSS periodic cell consists of a metallic square loop on the top metal layer and its complementary etched on the bottom metal layer separated by a thin dielectric layer. This designed FSS provides two tunable transmission bands. For predicting the frequency selective characteristics of the ...
Tópico(s): Metamaterials and Metasurfaces Applications
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Luiz da Silva Mello, M.S. Pontes,
In this paper, a semi-empirical method for the prediction of rain attenuation in slant paths and terrestrial links is proposed. The method uses the same simplified model of equivalent rain cell that is the basis for the ITU-R rain attenuation prediction methods but, additionally, the concept of an effective rain rate is introduced. This allows the use of the full rainfall rate distribution for the prediction of the rain attenuation distribution and the unification of the slant path and terrestrial ...
Tópico(s): Radio Wave Propagation Studies
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Verônica Franco Parreira, Danielle Soares Rocha Vieira, Mariana A. C. Myrrha, Isabela Maria Braga Sclauser Pessoa, Susan Martins Lage, Raquel Rodrigues Britto,
Optoelectronic plethysmography (OEP) is an innovative method of indirect measurement of pulmonary ventilation, capable of breath-by-breath, three-dimensional, real time assessment of absolute lung volumes and their variations in the three compartments of the chest wall (pulmonary rib cage, abdominal rib cage, and abdomen). OEP allows the measurement of variables of breathing pattern, breathing asynchrony, and contribution of each chest wall compartment and hemithorax to the tidal volume.To review ...
Tópico(s): Phonocardiography and Auscultation Techniques
2012 - Elsevier BV | Brazilian Journal of Physical Therapy
Daniele Tosi, Massimo Olivero, Guido Perrone,
In this paper, we propose a spectral correlation-based technique for tracking the wavelength shift of a fiber Bragg grating. We compared this approach, by means of a Monte Carlo numerical simulation, to the typical peak tracking techniques applied in classic interrogation systems. As result, we obtained a considerable gain in terms of noise tolerance (about 20 dB), which can be further incremented by selecting large-bandwidth gratings. This permits to increase the power budget of a fiber Bragg grating ...
Tópico(s): Semiconductor Lasers and Optical Devices
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
M. Rigoni, N. Sadowski, Nelson Jhoe Batistela, J.P.A. Bastos, S.L. Nau, A. Kost,
This paper presents measured data and electromagnetic FEM field calculations as techniques for detecting and analyzing eccentricity in three-phase induction motors. Also it presents experimental results for detecting broken bars in induction motor rotors. A search-coil is used as magnetic field sensor to measure the stray magnetic flux outside the motor. It is a totally non-invasive method.
Tópico(s): Magnetic Properties and Applications
2012 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
In this paper, single and dual band EBG structures for wider bandwidth are proposed. In each of the discussed EBGs, a metallic patch of regular geometry is chosen for the unit element. The patch is further modified by cutting slots to get extra inductance and capacitance which results into lower cut-off frequency and larger bandwidth. The proposed EBG structures are compared with the standard mushroom type EBG with respect to surface wave attenuation. The -20 dB cut-off frequencies and bandwidths ...
Tópico(s): Microwave Engineering and Waveguides
2014 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Simone Lucena, José Mário Aleluia Oliveira,
... e equipamentos), microeletrônica, telecomunicações, radiodifusão, engenharia genética e optoeletrônica. Essas tecnologias passaram a representar, a partir da ...
Tópico(s): Education and Digital Technologies
2014 - Programa de Pós-graduação em Geografia (PPGEO) | Revista Tempos e Espaços em Educação
Produção Nacional
Revisado por pares
Valdez A. Almeida Filho, Antônio Luiz P. S. Campos,
This paper presents the application of frequency selective surfaces in antenna arrays as an alternative to improve radiation parameters of the array. A microstrip antenna array between two FSS was proposed for application in WLAN and LTE 4G systems. Several parameters have been significantly improved, in particular the bandwidth, gain and radiation efficiency, compared with a conventional array. Numerical and measured results are presented.
Tópico(s): Antenna Design and Optimization
2014 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
M. Mejbaul Haque, Md Shamimur Rahman, Md. Samiul Habib, Md. Selim Habib, S. M. Abdur Razzak,
This paper presents a new circular photonic crystal fiber (C-PCF) for effective dispersion compensation covering E to L wavelength bands ranging from 1360-1625 nm. To investigate its guiding properties, finite element method (FEM) with a perfectly matched layer absorbing boundary condition is used. From our numerical simulation, it is found that the designed C-PCF simultaneously shows a large negative dispersion of about -248.65 to -1069 ps/(nm.km) over E to L wavelength bands and a relative dispersion ...
Tópico(s): Advanced Fiber Laser Technologies
2013 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Francisco Carlos Gurgel da Silva Segundo, Antônio Luiz P. S. Campos, Alfrêdo Gomes Neto,
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; by cascading them an UWB response is obtained covering the band 4.05 - 14.12 GHz, for vertical polarization and the band 5.05 - 15.00 GHz, for horizontal polarization. Transmission properties of the proposed structure were simulated and measured.
Tópico(s): Metamaterials and Metasurfaces Applications
2013 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
This paper presents the design of a nano-arm fractal antenna suitable for ultra wide band applications. The CPW-feed and fractal concept have been used to achieve the ultra wide bandwidth. The shape of the fractal geometry, the number of iterations and the number of nano-arms are the deciding factors for achieving wider impedance bandwidth. The experimental result of the fractal antenna exhibits ultra wideband characteristics in the frequency range of 2.55 GHz to 11.84 GHz corresponding to an impedance ...
Tópico(s): Microwave Engineering and Waveguides
2013 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
An optimized design for the spanner shape regular hexagonal monopole (RHM) patch antennas has been reported to yield ultra wide band (UWB) impedance bandwidth. Impedance and radiation characteristics are presented and discussed. From the results, it has been observed that, the impedance bandwidth, defined by 10 dB return loss, can reach a value of 8.63GHz. A rectangular slit in the radiating patch is used to reduce the lower-edge frequency resulting in improved bandwidth. This technique yields the ...
Tópico(s): Advanced Antenna and Metasurface Technologies
2013 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Francelli Klemba Coradin, Valmir de Oliveira, Márcia Müller, Hypólito J. Kalinowski, José Luís Fabris,
Thermal stability of both standard and regenerated Bragg gratings written in normal and photosensitive optical fibers was accessed. An apparent spectral wavelength stabilization of common gratings with no thermal hysteresis was reached after thermal treatments. However, after a time interval of 5 months, gratings exhibited a shift in the resonance Bragg wavelength at room temperature, as well as important changes in the thermal sensitivity above 200 ºC. Regenerated gratings proved to be stable only ...
Tópico(s): Semiconductor Lasers and Optical Devices
2013 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
In this paper, a novel design of a compact planar ultra wide band (UWB) monopole antenna with triple band notched characteristics has been presented. The antenna has a unique shape and has been fed through a 50 Ω microstrip feedline. The strength of the antenna lies in three band notched properties for WiMax system at 3.3 - 3.7 GHz, WLAN IEEE 802.11a at 5.15 - 5.85 GHz and X band satellite communication at 7.25 - 8.395 GHz. The notched bands have been achieved by incorporating an inverted U-slot etched ...
Tópico(s): Antenna Design and Optimization
2015 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
A compact (20 x 20 mm2 size), coplanar waveguide (CPW) fed, octagonal slotted, dual-band antenna is presented in this paper. The proposed antenna has a simple structure consisting of an octagonal slot, L-shape stub, and a two stepped rectangular patch. The introduction of the L-shaped metallic stubs in the ground plane generates a lower resonance frequency at 2.42 GHz. The proposed antenna is fabricated on a low cost FR4 substrate having thickness of 1.6 mm. The measured impedance bandwidth of the ...
Tópico(s): Bluetooth and Wireless Communication Technologies
2015 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Produção Nacional
Revisado por pares
Paulo José Abatti, Sérgio Francisco Pichorim, Caio M. de Miranda,
The condition for maximum power transfer of 2-coils wireless power transfer (WPT) system is derived from circuit analysis and discussed together with the respective WPT system efficiency (η). In the sequence, it is shown that a 4-coils WPT system (which can be divided in source, two communication and load circuits) without power losses at the two communication circuits (ideal 4-coils WPT system) presents, from maximum power transfer and efficiency point of view, a performance similar to those of a 2- ...
Tópico(s): Advanced Battery Technologies Research
2015 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Mahmoud Fallah, Alireza Ghayekhloo, Ali Abdolali,
In this article, a high-order frequency selective band-stop EMC (electromagnetic compatibility) shield is designed using multilayer square loop while each loop resonates at the specific desired frequency. The glass material is picked out as the preferred substrate for the designing process. In contrast to the computationally intensive numerical approaches (software), the equivalent circuit model offers a simple alternative method in FSS (frequency selective surface) analyses which is useful for quickly ...
Tópico(s): Metamaterials and Metasurfaces Applications
2015 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Layla Wakrim, Saïda Ibnyaich, Moha M’Rabet Hassani,
The ground plane plays an important role on the performance of a planar inverted-F antenna (PIFA).In this regard, the ground plane modification using slots is proposed in this research to obtain a dual band antenna for WiMAX application.Popular optimization techniques, as genetic algorithm (GA) and particle swarm optimization (PSO), were used to design the shape of the ground plane in order to improve the bandwidth and to achieve dual band antenna instead of single band antenna.The proposed method ...
Tópico(s): Advanced Antenna and Metasurface Technologies
2016 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Abdessamed Chinig, Ahmed Errkik, Larbi El Abdellaoui, Abdelali Tajmouati, Jamal Zbitou, Mohamed Latrach,
In this paper a novel design of microstrip diplexer and triplexer using open loop resonators is presented. The proposed diplexer if formed by two band-pass filters for the Industrial Scientific Medical (ISM) applications at 5.8 GHz and the WIMAX applications (IEEE 802.16 WiMAX at 3.17 GHz to 4.2 GHz bands). The microstrip triplexer is designed for the Digital Communication System (DCS) at 1.8 GHz, WIMAX at 3.2 GHz and for the C-band at 4.4 GHz. Each device is formed by a set of filters with a matching ...
Tópico(s): Antenna Design and Analysis
2016 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Ahmad H. Abdelgwad, Tarek M. Said,
Measurement of dielectric permittivity of soil has been studied by many researchers. However, few studies have been conducted on contaminated soil. The motivation of the present study is to investigate the behavior of sandy soil contaminated by lubricant oil at microwave frequency. Two different artificially prepared soil samples are measured in the laboratory. The measurement of the complex permittivity of soil samples is reported in the frequency range 500 MHz – 4 GHz using open-ended coaxial probe ...
Tópico(s): Microwave and Dielectric Measurement Techniques
2016 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications
Abdulrahman Amuda Yusuf, A.J. Falade, B. J. Olufeagba, Olatunji Obalowu Mohammed, Tharek Abd Rahman,
Substantial modifications have been made to the expressions for calculating distance factor and extrapolation techniques in the latest ITU-R P.530-14. However, its performance has not been rigorously evaluated in the tropical and equatorial climates. In this article, the new ITU-R method and three prediction models are validated using measurement data from tropical Malaysian climate. The data were collected on six geographically spread terrestrial microwave DIGI MINI-LINKs operating at 15 GHz. When ...
Tópico(s): Telecommunications and Broadcasting Technologies
2016 - Sociedade Brasileira de Microondas e Optoeletrônica; Sociedade Brasileira de Eletromagnetismo | Journal of Microwaves Optoelectronics and Electromagnetic Applications