{"title":"Pulse sharpening and RF generation using nonlinear transmission lines","authors":"L. P. Silva Neto, J. O. Rossi, J. Barroso","doi":"10.1109/IMOC.2015.7369106","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369106","url":null,"abstract":"A nonlinear lumped element transmission line (NLETL) with linear inductors and using capacitors as nonlinear elements was built to operate as a high voltage pulse sharpener. NLETLS are suitable for use in fast sampling pulse generation circuits and in the formation of high-voltage solitons, among other applications. In this paper, a NLETL built with 30 sections was tested up to 500 V providing a pulse rise reduction of 700 ns for an input rise time of about 2.5 μs on a 70 ohms resistive load when using a 1.2 kV IGBT solid state switch. Comparison of experimental results with Spice simulation from equivalent NLTL circuit modeling has shown good agreement.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124326266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Jost, C. Weickhmann, T. Franke, A. Prasetiadi, W. Hu, M. Nickel, O. Karabey, R. Jakoby
{"title":"Tuneable hollow waveguide devices for space applications based on liquid crystal","authors":"M. Jost, C. Weickhmann, T. Franke, A. Prasetiadi, W. Hu, M. Nickel, O. Karabey, R. Jakoby","doi":"10.1109/IMOC.2015.7369046","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369046","url":null,"abstract":"This paper presents an overview in the field of passive, continuously tuneable liquid crystal (LC) devices in hollow waveguide topology. In particular, the designs and measurements of a Ka-band phase shifter as well as a K-band band-pass filter based on an LC filled waveguide resonator are shown. Both demonstrators are designated to be space qualified as their field of application is in satellite communications. While the high performance phase shifter will be integrated in a phased array antenna for beam scanning purposes, the high quality (Q) factor band-pass filter will be used to change the operating frequency and band allocation of a satellite.The key feature of the LC based hollow waveguide phase shifter is its high efhciency, dehned by the maximum differential phase shift divided by the maximum insertion loss in all tuning states, which is measured in the design frequency range of 23 GHz to 27 GHz to more than 130°/dB by means of electric biasing. The key feature of the band-pass hlter is its high Q-factor of up to 484, resulting in a comparatively small bandwidth compared to common hlters based on planar topologies. For the presented hlter, a relative bandwidth of 1% is measured at 20 GHz.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121858371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. C. Ximenes, R. L. Silva, C. E. Castellani, M. Segatto, M. Pontes
{"title":"All-fibre transmission liquid level sensor based on core-cladding propagation modes interference","authors":"H. C. Ximenes, R. L. Silva, C. E. Castellani, M. Segatto, M. Pontes","doi":"10.1109/IMOC.2015.7369159","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369159","url":null,"abstract":"This paper presents an all-fibre liquid level sensor based on the interference between cladding and core modes propagating in a fibre with reduced core. The cladding modes are generated simply by using a combination of fibres with different cores fusion-spliced with a small misalignment. The sensing fibre is then exposed to the external medium and the level measurement is made by analysing only the transmitted signal, with no need for any special configuration to generate and collect a reflected signal. This simple, stable and compact system is capable of measuring up to 90 mm of water level with a sensitivity of 5.61 pm/mm with no need for using fibre gratings or fibre circulators.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122886438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. B. T. da Silva, H. D. de Andrade, Jose L. da Silva, H. Fernandes, M. P. de Sousa Neto, Jonathan P. P. Pereira
{"title":"Effects of Complementary Split Ring Resonator (CSRR) parameters in microstrip patch antenna characteristics","authors":"I. B. T. da Silva, H. D. de Andrade, Jose L. da Silva, H. Fernandes, M. P. de Sousa Neto, Jonathan P. P. Pereira","doi":"10.1109/IMOC.2015.7369104","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369104","url":null,"abstract":"This paper has the objective of study the insertion of a Complementary Split Ring Resonator (CSRR) in the ground plane of a microstrip patch antenna. The return loss, radiation diagram and magnetic field are evaluated according to the variations performed in CSRR's dimension. A good agreement between capacitive effect and the different dimensions used could be observed and an antenna with an effective frequency range filter could be achieved to prevent 802.11a and 802.11n interference, as part of X band frequency.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123380716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Giant Faraday rotation in cross-shaped graphene array in THz region","authors":"V. Dmitriev, Carlos Santos, C. Nascimento","doi":"10.1109/IMOC.2015.7369213","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369213","url":null,"abstract":"We study numerically the Faraday effect in cross-shaped graphene array. Our geometrical structure in the optimized configuration can provide the Faraday rotation of about 3° for the frequency 8.9 THz with a relatively low magnetic field of 1T and 13 ° for a magnetic fields of 10 T. These rotation value is about seven times higher than the results published until now. The frequency position of maximum Faraday rotation can be controlled by changing the Fermi energy of graphene or the dimensions of the array.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123420351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. E. Capovilla, J. Azcue, R. Jacomini, I. Casella, A. S. Filho
{"title":"A wireless coded OFDM neuro-fuzzy power control system for doubly-fed induction aerogenerators in smart grid applications","authors":"C. E. Capovilla, J. Azcue, R. Jacomini, I. Casella, A. S. Filho","doi":"10.1109/IMOC.2015.7369082","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369082","url":null,"abstract":"To provide balance supply, demand, and storage of energy over a region in a much more efficient manner than it is done today, smart grids will need to use an advanced communication infrastructure into a robust control system. Towards this objective, it is proposed in this work a wireless coded orthogonal frequency division multiplexing neuro-fuzzy power control employing low density parity check coding for a doubly-fed induction aerogenerator to improve system robustness and reliability. The performance improvements of the proposed system are investigated in a more realistic frequency selective fading propagation condition.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129127545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wamberto J. L. Queiroz, M. Alencar, W. Lopes, F. Madeiro
{"title":"Interference mitigation in anisotropic diffusion environments by using symmetric linear arrays","authors":"Wamberto J. L. Queiroz, M. Alencar, W. Lopes, F. Madeiro","doi":"10.1109/IMOC.2015.7369192","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369192","url":null,"abstract":"This paper presents an analysis of the mutual interference among users' equipment for channels with local scatterers, such as buildings, trees and other urban elements. In this scenario, the signals that arrive at a linear array with symmetric excitation of the array elements, considering the directions of arrival (DoA), are modelled using Gaussian and Uniform distributions. It is shown that the symmetric excitation of the array elements can reduce the mutual interference among users' transmitters, considering local scatterers' channels. Exact analytic expressions for the average power and the variance of the mutual interference are derived. Simulations results corroborate the analytic results.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125392372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. D. Silveira, Luana Silva Araujo, Thiago V. N. Coelho, A. Bessa dos Santos
{"title":"Considerations about the number of coefficients used in Volterra series models for RF Power Amplifiers","authors":"D. D. Silveira, Luana Silva Araujo, Thiago V. N. Coelho, A. Bessa dos Santos","doi":"10.1109/IMOC.2015.7369121","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369121","url":null,"abstract":"This article discusses further about the number of coefficients used in the many implementations of Volterra series models, performing a fair comparison between them, using measured data and known figures of merit found in the literature. Among the models implemented, a model that uses sub-sampling techniques allied to Volterra series in a parallel cascade structure aiming accuracy outperforms other variations of Volterra series models, with the drawback of using a higher number of coefficients. Based on the many figures of merit results, this article suggests new trends to be used in RF power amplifier behavioral models.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116404107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raquel Aline Araujo Rodrigues, Edmar Candeia Gurjão, F. M. de Assis, S. Tedjini, E. Perret
{"title":"Group delay analysis of folded multi-layer C-sections used in encoding of chipless RFID tag","authors":"Raquel Aline Araujo Rodrigues, Edmar Candeia Gurjão, F. M. de Assis, S. Tedjini, E. Perret","doi":"10.1109/IMOC.2015.7369145","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369145","url":null,"abstract":"Researches on modern wireless identification methods have been focused on RFID techniques and in particular on chipless solutions. A parametric study of folded multi-layer C-sections fabricated on flexible substrates and a chipless RFID tag with single group of folded C-sections are presented in this paper. Full-wave simulations have been done for the folded multi-layer C-section and the chipless RFID tag. The obtained results confirm the feasibility of the utilization of this concept with multi-layer C-sections in temporal multi-frequency encoding technique based on group delay. It has been found that the techniques with folded multi-layer structure offer a significant amount of group delay and highly narrow band delay peaks.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123769780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of High-Q dielectric resonators for wireless power transfer system","authors":"P. Belov, Mingzhao Song, I. Iorsh, P. Kapitanova","doi":"10.1109/IMOC.2015.7369228","DOIUrl":"https://doi.org/10.1109/IMOC.2015.7369228","url":null,"abstract":"We study the magnetic near field resonance wireless power transfer systems based on high refractive index dielectric resonators. We propose to operate at higher-order (multipole) modes of high refractive index dielectric resonators instead of magnetic dipole mode in the metallic coils and numerically demonstrate the higher efficiency due to minimization of the radiation losses. Moreover, the system operating at magnetic quadrupole mode is proved to be more stable to the mutual orientation of transmitter and receiver.","PeriodicalId":431462,"journal":{"name":"2015 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126389624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}