Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)最新文献

筛选
英文 中文
A VCO with harmonic suppressed and output power improved using defected ground structure 一种利用缺陷接地结构抑制谐波并提高输出功率的压控振荡器
Haiwen Liu, Xiaowei Sun, Zhengfan Li
{"title":"A VCO with harmonic suppressed and output power improved using defected ground structure","authors":"Haiwen Liu, Xiaowei Sun, Zhengfan Li","doi":"10.1109/IMOC.2003.1244851","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244851","url":null,"abstract":"In this paper, a novel defected ground structure (DGS) is proposed for suppressing harmonic and increasing the output power of a voltage-controlled oscillator (VCO) in microwave circuits. The DGS is formed with connecting in parallel two periodic structures which have different center frequencies (in a ratio of 2:3) of the stopband and provides the bandgap characteristic in certain frequency bands. Simulated and experimental results show that the microstrip line with DGS has a wide low-pass band for the fundamental frequency and a stopband for the second harmonic with good performance. To evaluate the effects of DGS on microwave VCOs, two GaAs field-effect transistor (FET) VCOs have been designed and fabricated. One of them has a 50/spl Omega/ microstrip line with DGS at the output section, while the other has only 50/spl Omega/ straight line. Measured results show that DGS suppresses the second harmonic more than -20dBm at the output and yields improved output power by 3-5%.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122937028","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}
引用次数: 7
Effect of temperature on the single mode fibers chromatic dispersion 温度对单模光纤色散的影响
P. André, A. Pinto, J. Pinto
{"title":"Effect of temperature on the single mode fibers chromatic dispersion","authors":"P. André, A. Pinto, J. Pinto","doi":"10.1109/IMOC.2003.1244863","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244863","url":null,"abstract":"We investigate the effect of temperature on optical fiber chromatic dispersion and chromatic dispersion slope, since these parameters affect dispersion compensation at high bit rates. We derive an expression for the chromatic dispersion slope variation with temperature as a function of the zero dispersion wavelength and chromatic dispersion slope at the zero dispersion wavelength. We also verify that this last term has a high contribution to the total chromatic dispersion variation, and can not be ignored. We show that the model of Ghosh et al for the silica refractive index temperature dependence can be used to describe the variation of the dispersion slope within the temperature interval between -40/spl deg/C and 60/spl deg/C. Through numerical simulation we verify that the effect of temperature cannot be ignored in the design of dispersion compensation devices for high bitrate systems (40 Gbit/s).","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116856092","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}
引用次数: 20
High precision measurement and generation of optical and microwave frequencies using narrowband and short-pulse lasers 高精度测量和产生光学和微波频率使用窄带和短脉冲激光
F. Cruz
{"title":"High precision measurement and generation of optical and microwave frequencies using narrowband and short-pulse lasers","authors":"F. Cruz","doi":"10.1109/IMOC.2003.1244870","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244870","url":null,"abstract":"Since the advent of the laser, more than forty years ago, the development of narrow-band single-frequency and high-spectral-purity sources has been quite separated from the efforts in the generation of short pulse, high-bandwidth mode-locked lasers. Today we have continuous-wave, single-frequency lasers with linewidths smaller than one Hertz, along with mode-locked lasers emitting pulses of only a few femtoseconds and whose spectra can cover an entire octave. These two classes of lasers have met recently in the field of metrology and nonlinear optics. It has been realized that the active control techniques traditionally used to reduce FM noise in single-frequency lasers, thus reducing their linewidths, could be used to stabilize the frequency comb which constitutes a mode-locked laser. By stabilization of both the repetition rate and the carrier-to-envelope offset of a femtosecond laser, a direct phase-coherent link between microwave and optical frequencies is possible, allowing for example the direct measurement of optical frequencies. A dramatic development from this has been the advent of optical atomic clocks. With stabilities and accuracies an order of magnitude higher than the conventional microwave clocks, they are opening a new era in precision measurements and will have great impact, for example, in navigation and telecommunications. Another close potential application is the development of optical frequency synthesizers, which can generate high-spectral-purity optical and microwave frequencies in a phase-coherent way. In this talk, an overview of these developments is given, along with the present status of our work towards frequency measurement and synthesis and the development of an optical atomic clock based on cold calcium atoms.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115413620","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}
引用次数: 0
A TD-MFIE for a vertically-polarized pulse propagation over irregular terrains 垂直极化脉冲在不规则地形上传播的TD-MFIE
R.B.V. Teperino, F. Moreira
{"title":"A TD-MFIE for a vertically-polarized pulse propagation over irregular terrains","authors":"R.B.V. Teperino, F. Moreira","doi":"10.1109/IMOC.2003.1244857","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244857","url":null,"abstract":"A time domain magnetic field integral equation (TD-MFIE) is developed and applied in the study of the propagation mechanisms of a vertically polarized electromagnetic pulse over an irregular ground. The atmosphere is assumed homogeneous and the conductivity of ground sufficiently small so to consider such ground a perfect magnetic conductor (PMC) for a vertical polarization. Furthermore, the terrain profile is assumed electrically smooth, such that back scattering is neglected and a forward scheme applied to obtain the surface magnetic currents of the equivalent problem, together with a marching-on-in-time (MOIT) technique to account for the time-varying characteristics.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115796854","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}
引用次数: 1
Analysis of some photonic crystal structures by using Bloch wave expansion 用布洛赫波展开法分析某些光子晶体结构
H. Hattori, R. M. Cazo, C. L. Barbosa, I. Ntakis
{"title":"Analysis of some photonic crystal structures by using Bloch wave expansion","authors":"H. Hattori, R. M. Cazo, C. L. Barbosa, I. Ntakis","doi":"10.1109/IMOC.2003.1244862","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244862","url":null,"abstract":"In this paper, some photonic crystal structures are analyzed by using MIT's MPB software. This software uses a Bloch-wave expansion to obtain the band diagrams for the devices. The band diagrams for a few examples are analyzed based upon the results of this numerical method.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126217803","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}
引用次数: 0
Eigencanceler study applied to local scatter channel model 局部散射信道模型的特征消去研究
Wamberto J. L. Queiroz, M. Alencar
{"title":"Eigencanceler study applied to local scatter channel model","authors":"Wamberto J. L. Queiroz, M. Alencar","doi":"10.1109/IMOC.2003.1244829","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244829","url":null,"abstract":"This paper presents a comparative study of the application of the eigenanalysis method in situations where the environment can be modeled as a circular cluster formed by the agglomeration of many scatters regularly distributed around the mobile station. The base station antenna array outside the circular cluster geographic area and the azimuthal arrival angles are considered random variables modeled respectively by Gaussian and uniform distributions for linear and circular array configurations. This type of channel model is frequently found in some urban areas, in WLL systems and indoor environments.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125085196","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}
引用次数: 0
Scattering matrix of the discontinuity between superquadric waveguides 超二次波导间不连续的散射矩阵
M. S. Novo, L. da Silva
{"title":"Scattering matrix of the discontinuity between superquadric waveguides","authors":"M. S. Novo, L. da Silva","doi":"10.1109/IMOC.2003.1244908","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244908","url":null,"abstract":"The mode matching technique is applied to the determination of the scattering matrix of the discontinuity between superquadric waveguides. The modal fields and cut-off wavenumbers of the waveguides are calculated by the variational method. Introduction of trigonometric functions as basis functions and imposition of a criteria to eliminate spurious modes, allow the accurate computation of more than 200 modes of a given waveguide, which is necessary to the envisaged application. Due to the versatility of the superquadric waveguides, that assume the form of cylindrical, elliptical, and rectangular waveguides, and intermediate shapes between them, it results in an efficient algorithm that can be applied in the analysis and design of several waveguide devices.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126296504","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}
引用次数: 1
High-Q dielectric combline resonator with wide spurious free performance 具有宽无杂散性能的高q介电组合谐振器
G. Shen, D. Budimir
{"title":"High-Q dielectric combline resonator with wide spurious free performance","authors":"G. Shen, D. Budimir","doi":"10.1109/IMOC.2003.1244894","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244894","url":null,"abstract":"Lower dielectric constant material loaded Combline resonators achieve high-Q and excellent spurious free performance is presented. A design and characteristics are discussed. Simulated responses are presented in this paper.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125299580","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}
引用次数: 2
Designing an RF front end radio receiver for educational purposes 设计一种用于教育用途的射频前端无线电接收机
G. O. Migowski, Jose C. A. Santos
{"title":"Designing an RF front end radio receiver for educational purposes","authors":"G. O. Migowski, Jose C. A. Santos","doi":"10.1109/IMOC.2003.1244910","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244910","url":null,"abstract":"The RF front end of a radio receiver was designed and implemented. The original receiver was designed for an L-band moving target indication (MTI) radar, from which we have developed this generic radio receiver for educational purposes. The aim of this work was to put into practice a novel insight into laboratorial practices in the electrical engineering courses at IME - an insight towards \"real-life\" situations. A simple design for the functional circuits allows an easier understanding of the circuit operation by graduate and undergraduate students. The work was developed so that the fabrication process could be well understood and of easy reproduction. Implementation costs as low as possible were also intended, since. future reproduction by undergraduate students was planned.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133111294","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}
引用次数: 2
Influence of transmission line transformer on the propagation characteristics of short electrical pulses 输电线路变压器对短电脉冲传播特性的影响
L.S. Demenicis, L. Conrado, D. L. A. Seixas, W. Margulis, M. Carvalho
{"title":"Influence of transmission line transformer on the propagation characteristics of short electrical pulses","authors":"L.S. Demenicis, L. Conrado, D. L. A. Seixas, W. Margulis, M. Carvalho","doi":"10.1109/IMOC.2003.1244895","DOIUrl":"https://doi.org/10.1109/IMOC.2003.1244895","url":null,"abstract":"The investigation of the propagation characteristics of short electrical pulses on transmission line transformers (TLT) was performed. The TLT considered here matches 50 /spl Omega/ to 3.5 /spl Omega/ and has Tchebysheff profile with 20 dB return loss. Time resolved results at various repetition rates showing consecutive pulses are presented. The resulting peak amplitude variation and undershoot introduced by the TLT on the pulses were analyzed and the influence of transmission rate and taper length were investigated.","PeriodicalId":156662,"journal":{"name":"Proceedings of the 2003 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference - IMOC 2003. (Cat. No.03TH8678)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133269152","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}
引用次数: 1
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信