Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169308
R. Penchel, J. Bergmann, F. Moreira
This work presents an extension of the formulation for the synthesis of dual-reflector antennas with omnidirectional coverage and arbitrary radiation pattern in elevation plane. The body-of-revolution subreflector is generated by a single conic section while the shaped main reflector is generated by a series of local conic sections sequentially consecutively concatenated. As case studies, four representative axis-displaced ellipse (ADE) configurations are synthesized to provide a sectoral coverage in the elevation plane. Two different ray structures are considered: with a real or a virtual main reflector caustic. The GO shaping results are validated using method-of-moments analysis.
{"title":"Omnidirectional ADE antennas with shaped main reflector described by local conic sections sequentially concatenated","authors":"R. Penchel, J. Bergmann, F. Moreira","doi":"10.1109/IMOC.2011.6169308","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169308","url":null,"abstract":"This work presents an extension of the formulation for the synthesis of dual-reflector antennas with omnidirectional coverage and arbitrary radiation pattern in elevation plane. The body-of-revolution subreflector is generated by a single conic section while the shaped main reflector is generated by a series of local conic sections sequentially consecutively concatenated. As case studies, four representative axis-displaced ellipse (ADE) configurations are synthesized to provide a sectoral coverage in the elevation plane. Two different ray structures are considered: with a real or a virtual main reflector caustic. The GO shaping results are validated using method-of-moments analysis.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114934966","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169237
J. P. T. da Fonseca, J. Gondek, G. Possetti, M. Muller, J. Fabris, R. C. Kamikawachi
In this work, are presented preliminary results of the application of an etched FBG as a sensor for analyzing the biodiesel quality. The method used is based on the thermo-optic effect and the spectral behavior when the refractive index of samples with different concentrations of biodiesel approaches the refractive index of the fiber cladding. The results show that the etched fiber Bragg gratings can be used to measure small concentrations of oil in biodiesel.
{"title":"Optical sensor based on etched fiber Bragg gratings for assessment of biodiesel quality","authors":"J. P. T. da Fonseca, J. Gondek, G. Possetti, M. Muller, J. Fabris, R. C. Kamikawachi","doi":"10.1109/IMOC.2011.6169237","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169237","url":null,"abstract":"In this work, are presented preliminary results of the application of an etched FBG as a sensor for analyzing the biodiesel quality. The method used is based on the thermo-optic effect and the spectral behavior when the refractive index of samples with different concentrations of biodiesel approaches the refractive index of the fiber cladding. The results show that the etched fiber Bragg gratings can be used to measure small concentrations of oil in biodiesel.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114941563","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169261
J. Barroso, U. Hasar
The constitutive parameters of a metamaterial slab showing negative refractive index over the 9–12 GHz frequency range are unambiguously retrieved from complex scattering parameters upon using the phase unwrapping method. Such a technique relies on properly adding to the phase of the complex transmission coefficient a stepwise function constructed from the resonance frequencies at which the phase of the transmission coefficient reaches ∓ π.
{"title":"Unambiguous determination of constitutive parameters of a metamaterial slab","authors":"J. Barroso, U. Hasar","doi":"10.1109/IMOC.2011.6169261","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169261","url":null,"abstract":"The constitutive parameters of a metamaterial slab showing negative refractive index over the 9–12 GHz frequency range are unambiguously retrieved from complex scattering parameters upon using the phase unwrapping method. Such a technique relies on properly adding to the phase of the complex transmission coefficient a stepwise function constructed from the resonance frequencies at which the phase of the transmission coefficient reaches ∓ π.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115012186","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169316
L. Inclán-Sánchez, E. Rajo-Iglesias, J. Vazquez-Roy, O. Quevedo–Teruel, S. Barbin
Planar hairpin resonators are considerably compact and can found numerous applications. One of them is its use as unit cell for designing different types of artificial surfaces based on periodic structures, such as EBGs or even “soft” surfaces. In this work we propose to include some varactor diodes in the unit cell with the purpose of providing reconfigurability to the structure in terms of operation frequency. The demonstrator is manufactured in a 1D multilayer version by using a microstrip line and analyzing the transmission parameter S21.
{"title":"Reconfigurable unit cell for EBG and artificial surfaces based on hairpin resonators","authors":"L. Inclán-Sánchez, E. Rajo-Iglesias, J. Vazquez-Roy, O. Quevedo–Teruel, S. Barbin","doi":"10.1109/IMOC.2011.6169316","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169316","url":null,"abstract":"Planar hairpin resonators are considerably compact and can found numerous applications. One of them is its use as unit cell for designing different types of artificial surfaces based on periodic structures, such as EBGs or even “soft” surfaces. In this work we propose to include some varactor diodes in the unit cell with the purpose of providing reconfigurability to the structure in terms of operation frequency. The demonstrator is manufactured in a 1D multilayer version by using a microstrip line and analyzing the transmission parameter S21.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134410719","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169331
A. Pacheco-Sánchez, M. Enciso-Aguilar, L. Rodriguez-Mendez, E. Ramírez-García
In this paper, a study of the minimum noise figure of a given SiGe Heterojunction Bipolar Transistor (HBT) varying the bias point at different frequencies is implemented; the study includes a comparison between results obtained from computational simulation and analytical expression with measurements reported previously.
{"title":"Modeling high-frequency noise behavior in a SiGe Heterojunction Bipolar Transistor for different bias","authors":"A. Pacheco-Sánchez, M. Enciso-Aguilar, L. Rodriguez-Mendez, E. Ramírez-García","doi":"10.1109/IMOC.2011.6169331","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169331","url":null,"abstract":"In this paper, a study of the minimum noise figure of a given SiGe Heterojunction Bipolar Transistor (HBT) varying the bias point at different frequencies is implemented; the study includes a comparison between results obtained from computational simulation and analytical expression with measurements reported previously.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116619037","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169279
A. Lages, M. Kawakatsu, V. Dmitriev
We propose and simulate in this work a planar elliptical ultra-wideband monopole antenna with high efficiency. High efficiency of the antenna is archieved by applying some geometrical modifications in the conventional monopole antenna, followed by parametric optimization. The corners of the ground plane were rounded, the feeding line was designed with trapezoidal shape and the notch, also of trapezoidal geometry, was positioned under the feeding line. Two models of this antenna are presented. One has as attractive feature an excellent impedance matching with return loss level lower than −22 dB and the other one has very good radiation pattern characteristics in the entire UWB region. Both models have total effiency greater than 97% within almost entire UWB band, flat gain characteristic and and small transmission distortion.
{"title":"Planar elliptical UWB monopole antenna with high efficiency","authors":"A. Lages, M. Kawakatsu, V. Dmitriev","doi":"10.1109/IMOC.2011.6169279","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169279","url":null,"abstract":"We propose and simulate in this work a planar elliptical ultra-wideband monopole antenna with high efficiency. High efficiency of the antenna is archieved by applying some geometrical modifications in the conventional monopole antenna, followed by parametric optimization. The corners of the ground plane were rounded, the feeding line was designed with trapezoidal shape and the notch, also of trapezoidal geometry, was positioned under the feeding line. Two models of this antenna are presented. One has as attractive feature an excellent impedance matching with return loss level lower than −22 dB and the other one has very good radiation pattern characteristics in the entire UWB region. Both models have total effiency greater than 97% within almost entire UWB band, flat gain characteristic and and small transmission distortion.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123779946","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169379
H. Fernandes, M. P. de Sousa Neto
The propagation characteristics of the rectangular microstrip patch antenna on metamaterial substrate are determined via full wave method, Transverse Transmission Line — TTL. Compared to other full wave methods, the TTL is an efficient tool to determine the resonant frequency, making possible a significant algebraic simplification of the equations involved in the process. Numerical results of resonant frequencies are found as functions of the metamaterial properties.
{"title":"Full-wave analysis of rectangular microstrip antenna on metamaterial","authors":"H. Fernandes, M. P. de Sousa Neto","doi":"10.1109/IMOC.2011.6169379","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169379","url":null,"abstract":"The propagation characteristics of the rectangular microstrip patch antenna on metamaterial substrate are determined via full wave method, Transverse Transmission Line — TTL. Compared to other full wave methods, the TTL is an efficient tool to determine the resonant frequency, making possible a significant algebraic simplification of the equations involved in the process. Numerical results of resonant frequencies are found as functions of the metamaterial properties.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124183000","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169313
Adilson Chinatto, C. Junqueira, J. Romano
This paper presents and describes a low-cost hardware implementation of smart antenna based on FPGA. Unlike systems using high-cost devices, the case herein uses a low-end FPGA for beamforming algorithm implementation, enabling smart antenna applications in practical and commercial problems, as for instance interference mitigation. The low-cost smart antenna array underwent two different types of tests, solving the beamforming problem by a non-adaptive algorithm and by a blind adaptive one. The desired beamforming is reached in both cases and interference mitigation is achieved in the second one.
{"title":"Low cost smart antenna array hardware implementation","authors":"Adilson Chinatto, C. Junqueira, J. Romano","doi":"10.1109/IMOC.2011.6169313","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169313","url":null,"abstract":"This paper presents and describes a low-cost hardware implementation of smart antenna based on FPGA. Unlike systems using high-cost devices, the case herein uses a low-end FPGA for beamforming algorithm implementation, enabling smart antenna applications in practical and commercial problems, as for instance interference mitigation. The low-cost smart antenna array underwent two different types of tests, solving the beamforming problem by a non-adaptive algorithm and by a blind adaptive one. The desired beamforming is reached in both cases and interference mitigation is achieved in the second one.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127369732","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169339
L. C. Moreira, J. F. Neto, W. Van Noije, S. Kofuji
This paper presents a design of an UWB PPM — Pulse Position Modulation transmitter based on a 1.8V, 0.18μm CMOS technology. We propose a pulse generator using modified Nand gate as a Phase Detector (PD) with an effective phase difference of 73ps. At the PD output an extra derivative circuitry exists. The whole circuit has been simulated using LTSpice and the results had demonstrated the circuit capability to operate as an impulse generator. The Gaussian impulse achieves a very small pulse width of about 192ps, and amplitude of 44mVpp, with power dissipation of 1μW. The complete circuit occupies area of 220×220 μm2 including the inductor, but without PADS.
{"title":"A PPM Gaussian transmitter for UWB using a compact phase detector","authors":"L. C. Moreira, J. F. Neto, W. Van Noije, S. Kofuji","doi":"10.1109/IMOC.2011.6169339","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169339","url":null,"abstract":"This paper presents a design of an UWB PPM — Pulse Position Modulation transmitter based on a 1.8V, 0.18μm CMOS technology. We propose a pulse generator using modified Nand gate as a Phase Detector (PD) with an effective phase difference of 73ps. At the PD output an extra derivative circuitry exists. The whole circuit has been simulated using LTSpice and the results had demonstrated the circuit capability to operate as an impulse generator. The Gaussian impulse achieves a very small pulse width of about 192ps, and amplitude of 44mVpp, with power dissipation of 1μW. The complete circuit occupies area of 220×220 μm2 including the inductor, but without PADS.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130022424","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}
Pub Date : 2011-10-01DOI: 10.1109/IMOC.2011.6169373
A. O. Rodrigues, J. J. Viana, J. A. Ramírez
This paper presents an implementation of the finite-difference time-domain (FD-TD) method in Java using CPML boundary conditions. The FD-TD code was validated with a canonical problem. The performance of the Java code was tested in half wavelength dipole in a 3D domain containing bone and brain. The results indicate that Java is appropriate for this kind of calculation due to its several advantages and for being significantly faster than Matlab with the same accuracy.
{"title":"A Java platform for the implementation of the finite-difference time-domain method","authors":"A. O. Rodrigues, J. J. Viana, J. A. Ramírez","doi":"10.1109/IMOC.2011.6169373","DOIUrl":"https://doi.org/10.1109/IMOC.2011.6169373","url":null,"abstract":"This paper presents an implementation of the finite-difference time-domain (FD-TD) method in Java using CPML boundary conditions. The FD-TD code was validated with a canonical problem. The performance of the Java code was tested in half wavelength dipole in a 3D domain containing bone and brain. The results indicate that Java is appropriate for this kind of calculation due to its several advantages and for being significantly faster than Matlab with the same accuracy.","PeriodicalId":179351,"journal":{"name":"2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128018550","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}
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