DOCSLIB.ORG

Middlesex University Research Repository

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Middlesex University Research Repository Middlesex University Research Repository An open access repository of Middlesex University research http://eprints.mdx.ac.uk Lei, Daiqing (1999) Multi-chip module interconnections at microwave frequencies: electromagnetic simulation and material characterisation. PhD thesis, Middlesex University. Available from Middlesex University’s Research Repository at http://eprints.mdx.ac.uk/13417/ Copyright: Middlesex University Research Repository makes the University’s research available electronically. Copyright and moral rights to this thesis/research project are retained by the author and/or other copyright owners. The work is supplied on the understanding that any use for commercial gain is strictly forbidden. A copy may be downloaded for personal, non- commercial, research or study without prior permission and without charge. Any use of the thesis/research project for private study or research must be properly acknowledged with reference to the work’s full bibliographic details. This thesis/research project may not be reproduced in any format or medium, or extensive quotations taken from it, or its content changed in any way, without first obtaining permission in writing from the copyright holder(s). If you believe that any material held in the repository infringes copyright law, please contact the Repository Team at Middlesex University via the following email address: [email protected] The item will be removed from the repository while any claim is being investigated. Mi~dles.ex University London " Middlesex University Research Repository: an open access repository of Middlesex University research http://eprints.mdx.ac.uk Lei, Daiqing, 1999. Multi-chip module interconnections at microwave frequencies: electromagnetic simulation and material characterisation. Available from Middlesex University's Research Repository. Copyright: Middlesex University Research Repository makes the University's research available electronically. Copyright and moral rights to this thesis/research project are retained by the author and/or other copyright owners. The work is supplied on the understanding that any use for commercial gain is strictly forbidden. A copy may be downloaded for personal, non-commercial, research or study without prior permission and without charge. Any use of the thesis/research project for private study or research must be properly acknowledged with reference to the work's full bibliographic details. This thesis/research project may not be reproduced in any format or medium, or extensive quotations taken from it, or its content changed in any way, without first obtaining permission in writing from the copyright holder(s). If you believe that any material held in the repository infringes copyright law, please contact the Repository Team at Middlesex University via the following email address: [email protected] The item will be removed from the repository while any claim is being investigated. Multi-chip Module Interconnections at Microwave Frequencies: Electromagnetic Simulation and Material Characterisation Daiqing Li Communication Research Group School of Computing Science Middlesex University January 1999 A thesis submitted to Middlesex University in partial fulfilment of the requirements for the degree of Doctor of~hilosophy Abstract In this work both the interconnections and materials used in multi-chip modules (MCMs) at microwave frequencies have been investigated. The electrical behaviour of the interconnections was studied using commercially available 2.SD and 3D electromagnetic simulators (HFSSTM, MDSTM and Momentum™). State-of-the-art conductive and dielectric film materials used in the fabrication of multi-layer MCM structures were characterized using microstrip/waveguide resonator techniques. The models chosen for simulation of interconnections are commensurate with those in current use in MCM technology. Crosstalk between microstrip conductors in multi-layer MCM structures was simulated and new knowledge leading to new design rules was obtained. Typical elements in MCM interconnect structures, such as vias, bends and airbridges were also investigated. The principal features of these elements were simulated and the results were obtained in S-parameter form. Based on the simulated results, these parasitic elements were modelled in terms of their equivalent circuits which can be used in circuit simulators to aid more rigorous MCM circuit design. A microstrip ring resonator, fabricated using the newly developed conductive material from Heraeus, was employed to measure the line loss. New techniques have been developed to measure the permittivity and loss tangent of thin dielectric films. In the previous methods for the measurement of these films, the accuracy in measuring the relative permittivity is limited and there is no available technique to measure the loss tangent. A novel cavity perturbation method was developed to accurately measure both the relative permittivity and loss tangent of the films deposited on a supporting substrate. An additional independent technique, derived from transmission line theory, for measuring the relative permittivity of dielectric film was also established. A particular feature of the new ii teclmiques, which led to high accuracy in measuring dielectric constant and loss tangent was the positioning of the dielectric film in the region of maximum electric field strength, thereby ensuring maximum interaction between the electric field and the film material. A rigorous error analysis was performed on the new techniques, which led to the establishment of practical measurement correction factors. A simple and rigorous method has also been developed to accurately measure the loss tangent of dielectrics with known dielectric constant using a resonant cavity. The novel method eliminates the need for any physical measurement of the dielectric sample. The new technique should permit the development of techniques for very high frequency characterisation of dielectric materials. iii Acknowledgements I thank my supervisors, Dr. Charles E. Free, Dr. Peter Barnwell and Keith E. G. Pitt for their encouragement and guidance during my research. I am also grateful to Heraeus Inc. for their financial support, sample preparation and technical information. Thanks also to my colleague K. P. Tang for his support in using CAD software and helpful discussions. I thank Martin Scott, Donald Thorpe, Pathma Gunasingham and Dave Court for their assistance in preparing samples and using clean room facilities. iv Table of contents Abstract 11 Acknowledgements IV Overview of thesis Xl Chapter 1 Introductions and literature review 1 1.1 Overview of multi-chip modules(MCMs) used at high frequencies 1 1.2 The aim of this study and the approaches adopted 4 1.2.1 Simulation and modelling of interconnections in MCMs 4 1.2.2 Characterisation of MCM materials at the microwave frequencies 5 Chapter 2 Crosstalk between microstrip lines in multi-chip modules(MCMs) 12 2.1 Introduction 12 2.2 The classification of MCM teclmologies 14 2.3 Microwave theory for parallel-coupled microstrip lines 17 2.4 Simulation techniques 19 2.5 Structures investigated using HFSSTM 22 2.6 Simulation and results 25 2.7 Conclusions 32 v Chapter 3 Simulation and modelling of vias in MCMs and high density packaging in microwave frequencies 35 3.1 Introduction 35 3.2 Structures under Investigation 36 3.3 Comparison between simulated and experimental results for a grounding via 42 3.4 Simulation of cylindrical, square and wedge-shaped vias 43 3.4.1 Simulated S-parameters of vias 43 3.4.2 Simulated phase change from vias 48 3.5 Modelling of vias by equivalent circuit 52 3.6 Conclusions 55 Chapter 4 Interactions between discontinuities in proximity in MCM interconnection in microwave frequencies 58 4.1 Introduction 58 4.2 Simulation and modelling of microstrip bends in MCM interconnection 59 4.2.1 HP Momentum: a 2.5-D multi-layer planar electromagnetic field solver 59 4.2.2 Simulation and modelling of a single microstrip bend 60 4.2.3 Two offset microstrip bends 63 4.2.4 Crosstalk between two microstrip bends 65 4.2.5 Summary for simulation and modelling of mi cro strip bends 69 4.3 Interaction between vias in MCM interconnection at microwave frequencies 70 4.3.1 Simulation of a standard cylindrical grounding via 70 4.3.2 Simulation of a 35 flm cylindrical via 72 vi 4.3.3 Investigation of a 35 11m cylindrical via connected by microstrip lines with Different angles 75 4.3.4 Two offset vias 79 4.3.5 Crosstalk between two individual vias in proximity 82 4.3.6 Summary for simulation of interaction between vias 84 4.4 Simulation of airbridge in high frequency, high density packaging 85 4.4.1 The effect of airbridge height on transmission behaviour 85 4.4.2 Characteristic impedance and phase constant of airbridge line 89 4.4.3 Simulated results for airbridge 92 4.4.4 Crosstalk between airbridge lines in proximity 96 4.4.5 Summary for simulation of airbridge lines 100 Chapter 5 Design rules for interconnections in mutichip modules 102 5.1 Design rules for the minimisation of crosstalk between conductor lines 102 5.2 Design rules for intercom1ect vias in multi-layer MCM structures 103 5.3 Design rules for airbridge line in MCM interconnections 104 5.4 Design rules for interaction between discontinuities in proximity in multi-layer MCM interconnections 104 Chapter 6 Characterisation of conductive materials using a ring resonator 106 6.1 Theory of micro strip ring resonator 106 6.2 Optimisation of coupling gap for microstrip ring resonator 109 6.3 Test results
Load more

Recommended publications
  • High Contrast Grating for Optical Sensing by Tianbo Sun A
    High Contrast Grating for Optical Sensing By Tianbo Sun A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Electrical Engineering and Computer Sciences in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Connie Chang-Hasnain, Chair Professor Ming C. Wu Professor Xiang Zhang Fall 2015 High Contrast Gratings for Optical Sensing © Copyright 2015 By Tianbo Sun All rights reserved Abstract High Contrast Gratings for Optical Sensing by Tianbo Sun Doctor of Philosophy in Engineering-Electrical Engineering and Computer Sciences University of California, Berkeley Professor Constance J. Chang-Hasnain, Chair Integrated optoelectronics has seen its rapid development in the past decades. It has been expanded to many emerging applications beyond optical communication, including environmental sensing, healthcare and remote sensing, etc. This revolutionary progress greatly benefits from device level innovation. High contrast gratings (HCG) is an emerging element in integrated optoelectronics. Compared to the other elements, HCG has a very rich properties and design flexibility. Two most extraordinary properties of HCG are broadband reflectivity and high quality factor resonance, which are highly desired to solve current challenges in the aforementioned applications. In this dissertation, we will explore the physical origins of the extraordinary features of HCG, and discuss its applications in optical sensing. Various device innovation for optical sensing, such as HCG slow light hollow-core waveguide for gas sensing, HCG resonator for bio-medical sensing, flexible surface plasma sensor , fast optical phase array and HCG-graphene spatial light modulator for remoting sensing are demonstrated with HCG as the enabling elements.
    [Show full text]
  • Reflection Coefficients in the TM Mode
    Research institute Research Group GeMMe Department ArGEnCo Faculty of Applied Sciences University of Liege, Belgium Thesis committee Prof. Luc Courard Université de Liège Advisor Prof. Frédéric Nguyen Université de Liège Co-advisor Prof. Eric Pirard Université de Liège President Prof. Jean-Paul Balayssac INSA Toulouse Prof. Andrzej Garbacz Politechnika Warszawska Prof. Jan van der Kruk Forschungszentrum Jülich Prof. André Plumier Université de Liège Funding This research has been supported by the F.R.S.-FNRS research fellow grant FC 84664. Copyright © 2014 Audrey Van der Wielen Citation: Van der Wielen, A. (2014). Detection and characterization of thin layers into concrete with Ground Penetrating Radar. PhD Thesis, University of Liège, Belgium, pp. XXX. Abstract The Ground Penetrating Radar (GPR) is a nondestructive technique increasingly used for the inspection of concrete structures. The method is well suited to study multilayer media, because only a part of the incident energy is reflected at each interface. But the quantitative determination of the thickness and properties of thin embedded layer remains an application under development, in particular when the tests are performed with contact antennas of high frequency. The aim of this work is to contribute to the development of a fast method for the thin layers determination, based on measurements performed with commercial antennas, by proposing an analytical estimation of the reflection coefficient. As a first step, the equations allowing to estimate the reflection coefficient on a simple interface were developed, taking into account the wave spherical reflection in the near field and the lateral wave propagation. Similarly, for thin layers, equations taking into account the multiple reflections on the interfaces can be developed with different approaches.
    [Show full text]
  • Meeting Abstracts
    Downloaded from orbit.dtu.dk on: Oct 08, 2021 Danish activities concerning noise in the environment (A) Ingerslev, Fritz Published in: Acoustical Society of America. Journal Link to article, DOI: 10.1121/1.2019901 Publication date: 1982 Document Version Publisher's PDF, also known as Version of record Link back to DTU Orbit Citation (APA): Ingerslev, F. (1982). Danish activities concerning noise in the environment (A). Acoustical Society of America. Journal, 72(S1), S45-S46. https://doi.org/10.1121/1.2019901 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. PROGRAM OF The 104thMeeting of theAcoustical Society of America SheratonTwin Towers ß Orlando,Florida ß 8-12 November1982 TUESDAY MORNING, 9 NOVEMBER 1982 BROWARD AND PALM BEACH ROOMS, 8:00TO 10:15A.M. SessionA.Underwater Acoustics I: The Impact of Satellite and Aerial Remote Sensing onthe Study of Ocean Acoustics Paul D. Scully-Power,Chairman Naval UnderwaterSystems Center, New London, Connecticut 06320 Chairman'sIntroduction4:00 Invited Papers 8:05 A1.
    [Show full text]
  • Millimeter-Wave Monitoring of Nuclear Waste Glass Melts – an Overview
    PSFC/JA-02-1 MILLIMETER-WAVE MONITORING OF NUCLEAR WASTE GLASS MELTS – AN OVERVIEW P. P. Woskov, J. S. Machuzak, P. Thomas, S. K. Sundaram1, and William E. Daniel2, Jr. January 2002 Plasma Science and Fusion Center Massachusetts Institute of Technology Cambridge, MA 02139 1 also with Pacific Northwest National Laboratory, Richland, WA 99352 2 Savannah River Technology Center, Aiken, SC 29808 This work was supported by the U. S. Department of Energy, Office of Science and Technology, Mixed Waste Focus Area. Reproduction, translation, publication, and use in whole or in part, by or for the United States government is permitted. To be published in the Proceedings of the 103rd Meeting of the American Ceramic Society MILLIMETER-WAVE MONITORING OF NUCLEAR WASTE GLASS MELTS – AN OVERVIEW P. P. Woskov, J. S. Machuzak, and P. Thomas Plasma Science and Fusion Center Massachusetts Institute of Technology Cambridge, MA 02139 S. K. Sundaram Pacific Northwest National Laboratory Richland, WA 99352 William E. Daniel, Jr. Westinghouse Savannah River Company Aiken, SC 29808 ABSTRACT Molten glass characteristics of temperature, resistivity, and viscosity can be monitored reliably in the high temperature and chemically corrosive environment of nuclear waste glass melters using millimeter-wave sensor technology. Millimeter-waves are ideally suited for such measurements because they are long enough to penetrate optically unclear atmospheres, but short enough for spatially resolved measurements. Also efficient waveguide and optic components can be fabricated from refractory materials such as ceramics. Extensive testing has been carried out at a frequency of 137 GHz to temperatures up to 1500 °C. Performance of refractory waveguides at high temperature has been shown to be satisfactory.
    [Show full text]
  • Low Profile UHF/VHF Metamaterial Backed Circularly Polarized
    Progress In Electromagnetics Research C, Vol. 60, 11–20, 2015 Low Profile UHF/VHF Metamaterial Backed Circularly Polarized Antenna Structure Taulant Rexhepi1, *, Igor Bendoym2, Ada-Simona Popescu1, Andrii Golovin1, Johnny Daniel3, Kate J. Duncan3, and David Crouse2 Abstract—In this work, a low-profile metamaterial backed planar antenna structure designed to work in the UHF/VHF range is presented. The antenna has right-hand circular polarization. It is ideal for satellite-based communications and radar systems. An artificial magnetic conductor was designed using a metamaterial composed of a split ring resonators to reduce the size of the planar antenna and ground plane system. The proposed artificial magnetic conductor has more confined surface waves at the reflecting plane than previous designs and is suitable for circular polarization. Through numerical simulations, performance characteristics including return-loss, and realized gain of the antenna systems are calculated and analyzed in the VHF range. The proposed antenna system is narrowband and is linearly scalable in the range of 100 MHz–1 GHz. 1. INTRODUCTION Over the recent decade, a major area of interest for microwave researchers has been the replacement of metallic electric-conducting ground planes of antennas with artificial magnetic material surfaces made from metamaterials [1–7]. With such structures, it was demonstrated that the distance between the antenna and the metal ground plane can be significantly reduced while maintaining the optimized gain [2]. The radiation emitted by a planar antenna has two components: a forward propagating component emitted in the direction of the receiver or target, and a backwards propagating component that, unless captured, would be wasted.
    [Show full text]
  • High Contrast Grating for Optical Sensing
    High Contrast Grating for Optical Sensing Tianbo Sun Constance Chang-Hasnain, Ed. Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2017-170 http://www2.eecs.berkeley.edu/Pubs/TechRpts/2017/EECS-2017-170.html December 1, 2017 Copyright © 2017, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. High Contrast Grating for Optical Sensing By Tianbo Sun A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Electrical Engineering and Computer Sciences in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Connie Chang-Hasnain, Chair Professor Ming C. Wu Professor Xiang Zhang Fall 2015 High Contrast Gratings for Optical Sensing © Copyright 2015 By Tianbo Sun All rights reserved Abstract High Contrast Gratings for Optical Sensing by Tianbo Sun Doctor of Philosophy in Engineering-Electrical Engineering and Computer Sciences University of California, Berkeley Professor Constance J. Chang-Hasnain, Chair Integrated optoelectronics has seen its rapid development in the past decades. It has been expanded to many emerging applications beyond optical communication, including environmental sensing, healthcare and remote sensing, etc. This revolutionary progress greatly benefits from device level innovation.
    [Show full text]
  • High Contrast Gratings for Integrated Optoelectronics
    High Contrast Gratings for Integrated Optoelectronics Weijian Yang Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2014-197 http://www.eecs.berkeley.edu/Pubs/TechRpts/2014/EECS-2014-197.html December 1, 2014 Copyright © 2014, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. High Contrast Gratings for Integrated Optoelectronics by Weijian Yang A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering-Electrical Engineering and Computer Sciences and the Designated Emphasis in Nanoscale Science and Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Constance J. Chang-Hasnain, Chair Professor Ming C. Wu Professor Xiang Zhang Professor Eli Yablonovitch Fall 2013 High Contrast Gratings for Integrated Optoelectronics © 2013 by Weijian Yang Abstract High Contrast Gratings for Integrated Optoelectronics by Weijian Yang Doctor of Philosophy in Engineering-Electrical Engineering and Computer Sciences and the Designated Emphasis in Nanoscale Science and Engineering University of California, Berkeley Professor Constance J. Chang-Hasnain, Chair Integrated optoelectronics has seen its rapid development in the past decade. From its original primary application in long-haul optical communications and access network, integrated optoelectronics has expanded itself to data center, consumer electronics, energy harness, environmental sensing, biological and medical imaging, industry manufacture control etc.
    [Show full text]
  • Multifocal Terahertz Lens with Adjustable Focal Points
    Multifocal Terahertz Lens with Adjustable Focal Points Ali Abdolali 1,*, Roya Kargar 1, and Kasra Rouhi 1 1 Applied Electromagnetic Laboratory, School of Electrical Engineering, Iran University of Science and Technology, Tehran, 1684613114, Iran E-mail: [email protected] Abstract The conventional lens's tunability drawback always restricts their application compared to the metasurface lens (metalens). On the other side, reconfigurable metalenses offer the benefits of ultrathin thickness and capable of tunability. Therefore achieving reconfigurable functionalities in a single metasurface has attracted significant research interest for potential terahertz (THz) applications. In this paper, an adjustable metasurface is presented using Vanadium dioxide (VO2) to manipulate the electromagnetic waves and provide the full reflection phase. The phase-change metasurface is composed of a VO2 nanofilm, a silicon spacer, and a gold layer embedded in the structure's bottom. By employing the reconfigurable metasurface with the specific phase distribution, the incident beam can converge to determined points in any arbitrary manner, including the number of the focal points, focal points location, and power intensity ratio. Numerical simulations demonstrate that the proposed reconfigurable metasurface can concentrate power on one or more than one focal point in reflection modes as expected. Additionally, the VO2-based metasurface can control concentration width in a real-time manner using a novel proposed method. The simulation and theoretical results are in good agreement to verify the validity and feasibility of 2-bit metalens design, which has considerable potential in wireless high-speed communication and super-resolution imaging. Keywords: Adjustable, Metalens, Metasurface, Phase-change, Vanadium dioxide 1. Introduction Metasurface, referring to the thin planar arrangement of artificial unit cells in the subwavelength scale, has presented versatile abilities in manipulating the amplitude, phase, and polarization of electromagnetic waves for various applications [1].
    [Show full text]
  • Limits of Modal Insensitivity for Laser Vibrometry, Spectral Reduction Requires Super-Symmetry
    Limits of Modal Insensitivity for Laser Vibrometry, Spectral Reduction Requires Super-symmetry Michael C. Kobold1 AUGUST 2014 Distribution unlimited and unclassified 1 Personal: [email protected], Work: Michael.C.Kobold @ Navy.mil, Code X-12, Science, Technology, Analysis and Simulation Department, NSWC Panama City Division, Naval Surface Warfare Center PCD, 110 Vernon Ave, BL 110, 3B24W, Panama City, FL, USA 32407-7001, O 850.230.7212, (after-hours M 321.591.3679) Modal Insensitivity ABSTRACT Laboratory measurements showed that identification (ID) and monitoring of objects using remote sensing of their vibration signatures are limited in a couple of rare cases. This work provides two necessary conditions to infer that the remote identification of common targets to within prescribed bounds is practical; failure to ID the spectrum is shown to be rare. Modal modulation of laser return produces data clusters for adequate spectral ID using slowly swept sine (SSS) and small deflection multi-modal (MM) analyses. Results using these completely different calculations lead to practical removal of a remote sensing concern, spectral “reduction” (SR) of return used for object ID. The optical return adequately provides structural mode ID for non-imaging detection and classification of vehicles. Calculations using a large spot size to completely paint the vibrating object provide insight for SR found in laboratory measurements which use spot size as a variable. Non-imaging analytical calculations comparing SSS and MM approximations match to second order. Numerical SSS and MM calculations show vibrating rectangular plates have spatially integrated (non-imaging) return that varies substantially among low-frequency vibration modes. The clustering of data from these two methods is a necessary condition for ID.
    [Show full text]
  • Independent Modulation of the Phase and Amplitude of Electromagnetic Waves Based on the Phase Change of VO 2 and Mode Coupling
    American Journal of Physics and Applications 2021; 9(4): 88-93 http://www.sciencepublishinggroup.com/j/ajpa doi: 10.11648/j.ajpa.20210904.13 ISSN: 2330-4286 (Print); ISSN: 2330-4308 (Online) Independent Modulation of the Phase and Amplitude of Electromagnetic Waves Based on the Phase Change of VO 2 and Mode Coupling Tianrui Pan, Yuan Pei, Maosheng Wang, Xiaojuan Xie, Wanxia Huang * School of Physics and Electronic Information & Anhui Province Key Laboratory of Optoelectronic Materials Science and Technology, Anhui Normal University, Wuhu, China Email address: *Corresponding author To cite this article: Tianrui Pan, Yuan Pei, Maosheng Wang, Xiaojuan Xie, Wanxia Huang. Independent Modulation of the Phase and Amplitude of Electromagnetic Waves Based on the Phase Change of VO2 and Mode Coupling. American Journal of Physics and Applications . Vol. 9, No. 4, 2021, pp. 88-93. doi: 10.11648/j.ajpa.20210904.13 Received : July 11, 2021; Accepted : August 2, 2021; Published : August 12, 2021 Abstract: Metasurfaces in a metal–semiconductor–metal configuration have been studied in multiple contexts, including perfect absorption and phase modulation. Nevertheless, limit progress has been achieved in independent phase modulation. To study further in this work, a metasurface composed of an Au film/ VO 2 film/ Au patch array with square holes was proposed in this paper. Through simulating and analysing the optical properties, simulated results indicated that an extremely switchable function can be realized by modulating the phase transition of VO 2, when VO 2 was in the metal (semiconductor) phase, the whole structure represented as ON (OFF) state. Additionally, the efficient modulation depth is approximately 99.6% for the y-polarization at a wavelength of 2.019 µm.
    [Show full text]
  • Electronic Tuning of Semiconductor Lasers with Multiple Quantum Well
    ELECTRONIC TUNING OF SEMICONDUCTOR LASERS WITH MULTIPLE QUANTUM WELL DEVICES Submitted to University of London in Fulfillment of the Requirements for the Degree of Philosophiae Doctor Thesis Author: BO CAI Thesis Supervisor: ALWYN SEEDS Department of Electronic and Electrical Engineering University College London Torrington Place, London WC1E 7JE October, 1991 1 ProQuest Number: 10797639 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10797639 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 Electronic Tuning of Semiconductor Lasers With Multiple Quantum Well Devices Abstract This thesis has been devoted to theoretical and experimental work on tunable semiconductor lasers, devices which play an important role in optical communication. The use of multiple quantum well (MQW) materials as tuning elements has been studied. In theoretical work the static and dynamic characteristics of single and multi-cavity tunable laser systems have been investigated in considerable detail. The various tuning structures were discussed. The refractive index change in MQW materials has been modelled and comparison between MQW and bulk materials has been made.
    [Show full text]
  • Wideband Circularly Polarized Planer Inverted-F Antenna Using Reactive Impedance Surface
    International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-1, November 2019 Wideband Circularly Polarized Planer Inverted-F Antenna using Reactive Impedance Surface Tejaswi Jadhav, Shraddha Deshpande using reflection phase regions for circular polarization [6], Abstract: A wideband circularly polarized (CP) planar [7]. The notched frequency can be adjusted by slit length in inverted-F antenna (PIFA) is proposed and designed using the L-shaped stub [8]. The novel PIFA with wideband reactive impedance surface (RIS) for mobile communication. impedance bandwidth [9] and new approach cuboid ridge PIFA with RIS is used for CP radiation, size reduction and inductive loading patch for improving the CP performance wideband of the proposed CP-PIFA. It is a different technique for [10]. The metamaterials based RIS has used in the slot-loaded improving the various performance parameters of the antenna, that is, narrow bandwidth, size reduction, and the axial ratio (AR). patch for optimization of the antenna [11]. HIS consists of The structure of circular polarized PIFA is designed, analyzed, periodically arranged 6 × 6 nested concentric square patches geometrically optimized, and implementation of the antenna to on the top layer of the substrate to produce two in-phase operate at 2.4 GHz WLAN bands. Finally, a proposed CP-PIFA is reaction bands [12]. L-shaped stub microstrip antenna with analyzed and simulated using full 3D electromagnetic OSA fed and a multilayer based an AMC reflector novel using high-frequency structure simulator (HFSS). The measured metamaterials structure RIS [13]. The lattice of 4 × 4 periodic impedance bandwidth of designing an antenna (S11) 10-dB is metallic square structure patch with RIS [14] the partially 1399 MHz (1.542-2.943 GHz) 58.29\%, simulated 3-dB axial ratio reacting surface (PRS) and the reactive impedance surface bandwidth is 870 MHz (1.639-2.50 GHz) 36.25\%, measured voltage standing wave ratio (VSWR) is 1.02 and the realized gain (RIS) used in the wideband microstrip antenna [15].
    [Show full text]