| Manuscript Title: | NF – FF Transformation with Helicoidal Scanning: an Effective Source Modelling for Elongated Antennas |
| Manuscript Id: | IJMOT-2008-5-1 |
| Abstract: | A proper source modelling tailored for elongated antennas is here proposed for developing an innovative probe compensated near-field – far-field transformation technique with helicoidal scanning. By employing such an effective modelling, instead of the spherical one, it is possible to significantly reduce the error related to the truncation of the scanning zone, since measurement cylinders with a diameter smaller than the source height can be used. Some numerical tests are reported for assessing the accuracy of the far-field reconstruction process and its stability with respect to random errors affecting the near-field data. |
| Authors: | F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, M. Migliozzi, and G. Riccio |
| Submitted On: | 5/7/2008 |
| Pages: | 275-282 |
| Action: | [Full Paper]
No. of Downloads: 12 |
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| Manuscript Title: | Diversity gain measurements for body-centric communication systems |
| Manuscript Id: | IJMOT-2008-5-2 |
| Abstract: | In this paper, the implementation of diversity schemes for on-body communication systems at 2.4GHz, 5.8 GHz and 10GHz is investigated. In these systems both the transmitter and the receiver are placed on the body and at a distance that depends on the application in use. Monopole antennas on square ground planes are used as a transmitting element and two monopoles on a common ground plane as a two-branch receiver. Measurements have been carried out in an anechoic chamber in order to verify the scattering and fading effects of the body itself on the radio communication channel. The acquired data have been post-processed by resorting to different signal combining techniques, in order to evaluate the diversity performance. Measurement results in terms of diversity gain are shown for a number of typical on-body radio links, when different body postures are considered. Repeatability has been verified and proved for all considered radio links. |
| Authors: | A.A. Serra, A. Guraliuc, P. Nepa, G. Manara and I. Khan, P.S. Hall |
| Submitted On: | 5/9/2008 |
| Pages: | 283-289 |
| Action: | [Full Paper]
No. of Downloads: 7 |
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| Manuscript Title: | Spherical Near Field Testing of Small Antennas from 800MHz to 18GHz |
| Manuscript Id: | IJMOT-2008-5-3 |
| Abstract: | Small antennas and other modern antenna applications are using increasingly higher frequencies while demanding very rapid development and testing cycles. A fast, reliable and accurate way to exhaustively determine antenna performance is based on spherical near field measurement techniques combined with probe array technology. This paper describes the innovative design aspects of a spherical near field measurement system that has recently evolved to cover the entire band from 800MHz to 18GHz. The use of diagnostic and analysis software modules for efficient antenna testing is also presented. |
| Authors: | L. J. Foged, F. Mioc, A. Giacomini, B. Bencivenga |
| Submitted On: | 5/26/2008 |
| Pages: | 290-294 |
| Action: | [Full Paper]
No. of Downloads: 8 |
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| Manuscript Title: | A hemi-spherical Ku-band fully electronic antenna for aircraft in flight entertainment |
| Manuscript Id: | IJMOT-2008-6-15 |
| Abstract: | This paper deals with the design achievements on an active antenna able to guarantee the link with the chosen geostationary satellite in Ku band in order to supply in flight entertainment services on aircraft. The aim is to realize a future affordable innovative commercial product based on an antenna system not containing any mechanical moving parts at the same time able to steer the beam as well as to align the polarization through the use of custom electronic device. |
| Authors: | A. Catalani, F. Di Paolo, M. Migliorelli, L. Russo, L. Flamini, G. Seghi, E. Limiti, S. Selleri, G. Toso, P. Angeletti |
| Submitted On: | 6/6/2008 |
| Pages: | 295-303 |
| Action: | [Full Paper]
No. of Downloads: 12 |
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| Manuscript Title: | Finite-Volume Time-Domain Method for Electromagnetic Modelling: Strengths, Limitations and Challenges |
| Manuscript Id: | IJMOT-2008-5-9 |
| Abstract: | The attractive features of the Finite-Volume Time-Domain (FVTD) method for the solution of Maxwell’s equations come from the application in unstructured polyhedral meshes combined with an explicit time stepping. This paper reviews current developments of the FVTD method and provides an assessment of its potential as a general-purpose electromagnetic simulation technique. A tutorial on the FVTD algorithm is given first, followed by a discussion of the strengths as well as of the limitations of the method. More generally, the challenges associated with a widespread use of conformal time-domain techniques are described. The addressed points are illustrated by a representative application of the method, which involves the detailed modelling of dielectric resonator antennas (DRAs) in several configurations. |
| Authors: | C. Fumeaux, D. Baumann, G. Almpanis, E.P. Li, R. Vahldieck |
| Submitted On: | 5/15/2008 |
| Pages: | 318-328 |
| Action: | [Full Paper]
No. of Downloads: 6 |
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| Manuscript Title: | Circuit Modeling and Physical Interpretation of Substrate Integrated Waveguide Structures for Millimeter-Wave Applications |
| Manuscript Id: | IJMOT-2008-5-26 |
| Abstract: | This paper presents the most recent developments and achievements in the field of Substrate Integrated Waveguide (SIW) technology. Particular attention is paid to the physical interpretation of the operation principles and loss mechanisms of SIW interconnects and components. Some efficient techniques for the modeling and design of millimeter-wave SIW circuits and structures are presented and discussed, including full-wave analysis approaches and design methods based on equivalent circuit models. |
| Authors: | Maurizio Bozzi, Feng Xu, Luca Perregrini, Ke Wu |
| Submitted On: | 5/9/2008 |
| Pages: | 329=338 |
| Action: | [Full Paper]
No. of Downloads: 19 |
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| Manuscript Title: | 20/30GHz compact dual band circular polarizer for satellite feed systems |
| Manuscript Id: | IJMOT-2008-4-27 |
| Abstract: | A compact solution for a dual band OMT polarizer that avoids the use of additional iris loaded corrugated sections is discussed here. The proposed device is based on a conventional septum type polarizer-OMT in waveguide technology covering two separate bands, were an extension of its normal (rather narrow) frequency band of operation has been achieved to meet restringing specifications for the 20/30 GHz 5% fractional bandwidth satellite link communication bands. The septum type OMT-polarizer consists of three physical ports: two of them in rectangular waveguide and another common port in circular or square waveguide. A given signal coming from a rectangular port is split into two 3dB orthogonal signals at the common port with a time delay of 90º between them. This produces a circular polarized signal: a RHCP associated to one of the rectangular ports and a LHCP associated to the second rectangular port. This compact design exhibits good return losses (>25dB) at the rectangular and circular ports as well as high isolation (>40dB) between modes. Furthermore, axial ratio is kept as low as 0.5dB in both communication bands. |
| Authors: | A. Tribak, N. Fernandez, A. Mediavilla, F. Marante, M. Boussouis |
| Submitted On: | 4/8/2008 |
| Pages: | 339-344 |
| Action: | [Full Paper]
No. of Downloads: 17 |
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| Manuscript Title: | New Technologies for Future Flexible Satellite Payloads: Where are we? |
| Manuscript Id: | IJMOT-2008-4-16 |
| Abstract: | As the telecommunication market continuously increases, proposed services are more and more significant and diversified. Today, most of commercial satellite payloads are designed for a predetermined service, with a given mission, a fixed coverage, a fixed frequency plan and a fix power resource allocation. As a next step, it is not surprising if many actors in the field are now calling for much more flexibility to overcome all these limitations. This new trend will certainly benefit from the emergence of new concepts and new technologies in the field of microwave electronics. The satellite repeater offers a playground to insert technical novelties. There, local oscillators, filters and amplifiers, to name quite a few, can be improved with the use of several new technologies. |
| Authors: | Jean-Louis Cazaux, Marziale Feudale, Claude Drevon, Jean-François Villemazet, Sergio Di Nardo, Olivier Vendier, Stéphane Forestier |
| Submitted On: | 4/18/2008 |
| Pages: | 251-255 |
| Action: | [Full Paper]
No. of Downloads: 7 |
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| Manuscript Title: | Enhanced bandwidth and dual-band microwave components based on resonant-type metamaterial transmission lines |
| Manuscript Id: | IJMOT-2008-5-4 |
| Abstract: | In this paper, bandwidth enhancement in planar microwave components based on metamaterial transmission lines is discussed. The principle for bandwidth enhancement as well as the intrinsic limitations to enhance bandwidth will be presented. Specifically, it will be shown that it is not possible to enhance the operative bandwidth of microwave components in general, but significant improvement can be achieved if certain conditions are fulfilled. An example to illustrate bandwidth enhancement is provided. It consists on a balun based on the resonant type approach of metamaterial transmission lines, that is, transmission lines loaded with complementary split ring resonators (CSRRs). Size reduction and full compatibility with planar technology are other interesting aspects of the proposed bandwidth enhancement technique. The paper will also include a discussion on the possibility of using dispersion engineering to implement dual-band components based on CSRR-loaded metamaterial transmission lines. A dual-band power divider will be proposed as an illustrative example of the approach. |
| Authors: | G. Sisó, J. Bonache, M. Gil and F. Martín |
| Submitted On: | 5/5/2008 |
| Pages: | 345-352 |
| Action: | [Full Paper]
No. of Downloads: 17 |
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| Manuscript Title: | Study and Fabrication of Metamaterials for Electronics and Telecommunications Applications |
| Manuscript Id: | IJMOT-2008-5-22 |
| Abstract: | The research activities developed by five Italian academic partners (Universities of Roma Tre and “La Sapienza”, Sannio, Salerno, and Naples “Federico II”) in the frame of a PRIN 2006 research project, supported by the “Ministero dell’Università e della Ricerca,” are presented. The project involves theoretical investigation, numerical analysis, fabrication, and experimental characterization of metamaterials and (quasi-) periodic structures for applications in electronic devices and telecommunication systems. After a brief introduction about the main goals of the project, the scientific results achieved by the different research units will be detailed. |
| Authors: | A. Andreone, F. Frezza, V. Galdi, A. Scaglione, and L. Vegni |
| Submitted On: | 5/4/2008 |
| Pages: | 352-362 |
| Action: | [Full Paper]
No. of Downloads: 10 |
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| Manuscript Title: | Design, Fabrication and On-Wafer Characterization of a Meta-Material Transmission Line Coupler |
| Manuscript Id: | IJMOT-2008-5-28 |
| Abstract: | The design method based on analytical and electromagnetic simulations of a directional coupler consisting of CPW (CoPlanar Waveguide) CRLH (Composite Right/Left-Handed) TLs (Transmission Lines) is presented. The technological realization and the electrical performances of the coupler are also presented. |
| Authors: | S. Simion, R. Marcelli, G. Bartolucci, G. Sajin |
| Submitted On: | 5/8/2008 |
| Pages: | 363-369 |
| Action: | [Full Paper]
No. of Downloads: 6 |
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| Manuscript Title: | Guiding and Bending Light at Will with Spatial Solitons in Liquid Crystals |
| Manuscript Id: | IJMOT-2008-4-5 |
| Abstract: | We review state of the art and recent results in the controlled deflection of (2D+1) nematicons, i. e. optical spatial solitons generated through molecular reorientation in nematic liquid crystals. |
| Authors: | G.Assanto,M.Peccianti,A.Alberucci,A.Piccardi |
| Submitted On: | 4/22/2008 |
| Pages: | 370-376 |
| Action: | [Full Paper]
No. of Downloads: 18 |
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| Manuscript Title: | Modeling of Picoseconds Pulse Propagation in Optically Controlled MIS Microstrip Slow Wave Structures |
| Manuscript Id: | IJMOT-2008-5-19 |
| Abstract: | We have studied picosecond pulse propagation in an optically controlled metalinsulator-semiconductor (MIS) microstrip slowwave structure using equivalent transmission line model based on quasi-static approach which does not require exact field solutions by rigorous wave analysis. The model is quite accurate and may be used as a simple, accurate and fast method to study pulse propagation in MIS slow wave structures. The pulse obtained by the equivalent transmission line model, matches well with those predicted by a rigorous wave analysis and gives better insight to understand the behaviour pulse in MIS structure. |
| Authors: | Avanish Bhadauria, Enakshi Khular Sharma, B. R. Singh, Anil K. Saini |
| Submitted On: | 5/10/2008 |
| Pages: | 382-389 |
| Action: | [Full Paper]
No. of Downloads: 8 |
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| Manuscript Title: | Electrically Tunable Photonic True Time Delay Lines Employing Chirped Fiber Bragg Gratings |
| Manuscript Id: | IJMOT-2008-5-20 |
| Abstract: | In this contribution, a photonic true time delay (PTTD) based on linearly chirped fiber Bragg gratings (LCFBG) is described and experimental results are presented. The PTTD unit, uses a single wavelength laser source, exploiting the distributed photonic bandgap offered by the Linearly Chirped Fiber Bragg Grating to provide different time delays by properly actuating the physical and geometrical features of the LCFBG through temperature changes. The time delay response of the TTD unit has been characterized experimentally highlighting multiband operation capability (S, C, X and Ku bands) with ps time delay resolution and a maximum dynamic range of 250ps. Moreover the performance of a reconfigurable arbitrary waveform generator (AWG), employing such a PTTD unit is evaluated using a numerical approach. The spectral purity and deviation from linearity of high speed signals generated from the implemented AWG schematic are shown. |
| Authors: | M. Pisco, M. Spirito, S. Campopiano, A. Cusano , A. Cutolo |
| Submitted On: | 5/16/2008 |
| Pages: | 390-396 |
| Action: | [Full Paper]
No. of Downloads: 8 |
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| Manuscript Title: | Analysis of Discontinuities in Two-Dimensional Photonic Crystal Waveguides Using Floquet Modes Concept |
| Manuscript Id: | IJMOT-2008-5-23 |
| Abstract: | A numerical approach for analyzing the discontinuities in photonic crystal waveguides are proposed. The method uses a technique of concatenation between the local normal modes and the Floquet modes through the scattering matrices based on the Fourier mode analysis. Numerical examples for three kinds of discontinuities are presented for demonstrating the effectiveness of the proposed method. |
| Authors: | K. Yasumoto, K. Watanabe |
| Submitted On: | 5/10/2008 |
| Pages: | 397-403 |
| Action: | [Full Paper]
No. of Downloads: 9 |
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| Manuscript Title: | Ge-on-Si photodetectors for optical receivers |
| Manuscript Id: | IJMOT-2008-4-25 |
| Abstract: | We report on near infrared photodetectors based on germanium on silicon, for high-speed optical receivers. After summarizing design issues, we review the most recent results on pure-Ge-on-Si heteroepitaxy and discuss the link between material quality and device performance, with reference to recent achievements. Finally, we describe our approach to fast Ge/Si p-i-n detectors based on chemical vapor deposition. These detectors exhibit responsivities of 0.4 and 0.2A/W at 1.3 and 1.55µm, respectively, and operate at 10Gbit/s. |
| Authors: | Lorenzo Colace, Gaetano Assanto |
| Submitted On: | 4/28/2008 |
| Pages: | 404-411 |
| Action: | [Full Paper]
No. of Downloads: 9 |
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| Manuscript Title: | Influence of Intra Cavity Attenuation on the Linewidth of an Erbium Doped Fiber Ring Laser |
| Manuscript Id: | IJMOT-2008-5-31 |
| Abstract: | A tunable erbium doped fiber ring laser is constructed by controlling the intra cavity loss without the use of wavelength selective filters. For a given pump power, the linewidth of such a filterless laser is a function of the intra cavity loss. The linewidth characteristics in the C and L bands are independently observed and analysed. The results of numerical simulations of fiber ring laser are used to analyse the linewidth characteristics observed in the C band. The characteristics in the L band are interpreted qualitatively through the spectral dependence of the threshold power. The linewidth characteristics of a filter-less modelocked fiber laser are also addressed. |
| Authors: | Deepa Venkitesha, Vijaya Ramarao |
| Submitted On: | 5/8/2008 |
| Pages: | 412-418 |
| Action: | [Full Paper]
No. of Downloads: 8 |
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