Download or read book CFDTD Solution For Large Waveguide Slot Arrays written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Finite Difference Time Domain (FDTD) technique consists of simulating time varying electromagnetic fields in various media with Maxwell's curl equations in the form of finite difference equations, which are then used in a leapfrog fashion to incrementally advance the discretized electromagnetic fields forward in time and solve for them at alternating intervals in space. The main drawback to the use of the FDTD method is the need for large computational resources, notably memory. The amount of memory required is a function of the grid employed to divide the problem space into individual cells. The memory requirements increase with the volume in the computational domain. The Conformal FDTD (CFDTD) code is being developed jointly by RMA and the Navy for direct simulation of large complicated structures such as slotted waveguide array antennas. The ability to run on a parallel computing system and its highly versatile non-uniform meshing tool are two aspects of CFDTD that ease otherwise restrictive computational resource demands. CFDTD code performance including partitioning for parallel processing and computing runtimes are presented herein.

Download or read book Design of Resonant Waveguide Slot Arrays written by Henry Hoang Vo and published by . This book was released on 2008 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a novel approach for center feed resonant waveguide slot array design by using High Frequency Structure Simulator (HFSS) software. The goal is to develop a design procedure for the waveguide slot array (WGSA) in terms of resonant slot length, offset, and rotation as a function of the desired normalized slot conductances and/or resistances which are determined by the given aperture illumination.

Download or read book Advanced FDTD Methods written by Wenhua Yu and published by Artech House. This book was released on 2011 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced FDTD Methods: Parallelization, Acceleration, and Engineering Applications -- Contents -- Preface -- Chapter 1 Computational Electromagnetic Methods -- 1.1 FDTD METHOD -- 1.1.1 FDTD Update Equations -- 1.1.2 Stability Analysis -- 1.1.3 Boundary Conditions -- 1.2 METHOD OF MOMENTS -- 1.3 FINITE ELEMENT METHOD -- 1.3.1 Scalar Formulation -- 1.3.2 Vector Formulation -- 1.4 FINITE INTEGRATION TECHNIQUE -- References -- Chapter 2 FDTD Optimization and Acceleration -- 2.1 INTRODUCTION TO CPU ARCHITECTURE -- 2.2 SSE INSTRUCTION SET -- 2.3 CACHE OPTIMIZATION -- 2.4 TASK PARALLELIZATION AND BUNDLING -- 2.5 PREFETCH -- 2.6 READING OR WRITING COMBINATION -- 2.7 MATERIAL LOOP-UP TABLE -- 2.8 NUMA OPTIMIZATION -- 2.9 IMPLEMENTATION OF VALU FDTD METHOD -- References -- Chapter 3 Parallel FDTD Method and Systems -- 3.1 PARALLEL FDTD METHOD -- 3.2 OPENMP FOR MULTICORE PROCESSORS -- 3.3 MPI TECHNIQUE -- 3.4 NETWORK CARD, SWITCH, AND CABLE -- References -- Chapter 4 Electromagnetic Simulation Techniques -- 4.1 MESH GENERATION TECHNIQUES -- 4.2 BASIC SIMULATION PROCEDURE -- 4.3 DIPOLE ANTENNA -- 4.4 VIVALDI ANTENNA SIMULATION -- 4.5 BANDED MICROWAVE CONNECTOR -- 4.6 PARALLEL LINES -- 4.7 TWO-PORT ANTENNA -- 4.8 SLOT COUPLING -- 4.9 MICROWAVE FILTER -- 4.10 OPTIMIZATION AND PARAMETER SCAN -- 4.11 PERIODIC STRUCTURE SIMULATION -- 4.12 GROUND PENETRATING RADAR MODEL -- 4.13 MICROWAVE CONNECTOR -- References -- Chapter 5 EM Simulation Software Benchmarks -- 5.1 BASIC STEPS IN EM SIMULATION -- 5.1.1 HFSS -- 5.1.2 CST -- 5.1.3 FEKO -- 5.1.4 GEMS -- 5.2 HARDWARE PLATFORMS -- 5.3 PATCH ANTENNA -- 5.4 VIVALDI ANTENNA -- 5.5 SCATTERING OF DIELECTRIC SPHERE -- 5.6 CELL PHONE ANTENNA -- 5.7 ELECTROMAGNETIC BANDGAP STRUCTURE -- 5.8 STANDARD SAR TEST -- 5.9 WAVEGUIDE FILTER -- References -- Chapter 6 Large Multiscale Problem Solving -- 6.1 RADIO FREQUENCY PROTECTION.

Download or read book Higher Order FDTD Schemes for Waveguides and Antenna Structures written by Nikolaos V. Kantartzis and published by Morgan & Claypool Publishers. This book was released on 2006-12-01 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication provides a comprehensive and systematically organized coverage of higher order finite-difference time-domain or FDTD schemes, demonstrating their potential role as a powerful modeling tool in computational electromagnetics. Special emphasis is drawn on the analysis of contemporary waveguide and antenna structures. Acknowledged as a significant breakthrough in the evolution of the original Yee's algorithm, the higher order FDTD operators remain the subject of an ongoing scientific research. Among their indisputable merits, one can distinguish the enhanced levels of accuracy even for coarse grid resolutions, the fast convergence rates, and the adjustable stability. In fact, as the fabrication standards of modern systems get stricter, it is apparent that such properties become very appealing for the accomplishment of elaborate and credible designs.

Download or read book DIELECTRIC LOADED WAVEGUIDE SLOT ARRAYS written by Howard S JONES (Jr) and published by . This book was released on 1965 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of slotted arrays that utilizes the principle of dielectric loaded waveguide is described. The physical design of these arrays for operatioon at C-, S-, and L-band frequencies is characterized by their unusually small volume. Design techniques, dielectric material characteristics, and theoretical concepts for practical array-designs are discussed. Simplified methods of construction are outlined, and the performance of each design type is presented. This includes data on design parameters, voltage standing wave ratio, and radiation pattern characteristics. These dielectricloaded slot arrays offer substantial savings in volume, weight, and overall cost when compared with their conventional counterpart. A typical design (0.125 x 1.20 x 10.5 in.) at 5.4 Gc has a gain of 12.0 db, 16-deg elevation beamwidth, sidelobe level below 22 db, and a VSWR less than 1.5 over a 10-percent bandwidth. (Author).

Download or read book IETE Technical Review written by and published by . This book was released on 2000 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book FDTD Modelling for Wireless Communications written by Seppo Aukusti Saario and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of the finite-difference time-domain (FDTD) method for the numerical analysis of complex electromagnetic problems related to wireless communications is considered. Since exact solutions to many complex electromagnetic problems are difficult, if not impossible, the FDTD method is well suited to modelling a wide range of electromagnetic problems. Structures considered include single and twin-slot antennas for millimetre-wave applications, monopole antennas on mobile handsets and chokes for the suppression of currents on coaxial cables. Memory efficient techniques were implemented for the split-field perfectly matched layer (PML) absorbing boundary condition. The frequency-domain far-field transformations were used for the calculation of far- field radiation patterns. Dipole, slot and mobile handset antenna benchmark problems verified the accuracy of the FDTD implementation. The application of slot antennas for millimetre-wave imaging arrays was investigated. An optimal feed network for an offset-fed single-slot antenna was designed for the X band with numerical and experimental results in excellent agreement. A twin-slot antenna structure reduced surface wave coupling by 7.6 dB in the substrate between coplanar waveguide-fed slot antenna elements in a planar array. The reduction of substrate surface waves for the twin-slot antenna allows for closer element spacings with less radiation pattern degradation in array applications. Suppression techniques for currents flowing on the exterior surface of coaxial cables were investigated. These include the use of ferrite beads and a quarter-wave sleeve balun. The frequency dependent behaviour of ferrite based chokes showed highly resonant effects which resulted in less than 5 dB of isolation at the resonant frequencies of the bead. An analysis of air-gaps between the ferrite bead and cable are shown to be extremely detrimental in the isolation characteristics of ferrite bead chokes. An air-gap of 0.5 mm can reduce the isolation effectiveness of a bead by 20 dB. The first rigorous analysis of a quarter-wave sleeve balun is presented, enabling an optimal choke design for maximum isolation. A standard 0.25[symbols] sleeve balun achieved 10.9 dB isolation with [symbols]=4, whereas a choke of optimal length 0.232[symbols] had an isolation of better than -20 dB. Several techniques for the measurement of antenna characteristics of battery powered handsets were compared and perturbation effects associated with the direct connection of a coaxial cable to a mobile handset was quantified. Significant perturbation in both return loss and radiation pattern can occur depending on cable location on the handset chassis. The effectiveness of ferrite chokes in any location was marginal. However, the application of an optimal quarter-wave sleeve balun in the centre of the largest plane of the handset, orthogonal to the primary polarisation resulted in minimal perturbation of both radiation patterns and return loss.

Download or read book Finite Element Analysis of Antennas and Arrays written by Jian-Ming Jin and published by John Wiley & Sons. This book was released on 2009-02-23 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Most Complete, Up-to-Date Coverage of the Finite Element Analysis and Modeling of Antennas and Arrays Aimed at researchers as well as practical engineers—and packed with over 200 illustrations including twenty-two color plates—Finite Element Analysis of Antennas and Arrays presents: Time- and frequency-domain formulations and mesh truncation techniques Antenna source modeling and parameter calculation Modeling of complex materials and fine geometrical details Analysis and modeling of narrowband and broadband antennas Analysis and modeling of infinite and finite phased-array antennas Analysis and modeling of antenna and platform interactions Recognizing the strengths of other numerical methods, this book goes beyond the finite element method and covers hybrid techniques that combine the finite element method with the finite difference time-domain method, the method of moments, and the high-frequency asymptotic methods to efficiently deal with a variety of complex antenna problems. Complemented with numerous examples, this cutting-edge resource fully demonstrates the power and capabilities of the finite element analysis and its many practical applications.

Download or read book An Investigation of Coupling Effects in Waveguide Slot Arrays written by P. Nacaskul and published by . This book was released on 1962 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A quantitative comparison of broad wall waveguide slot arrays for heating of lossy dielectrics at 2 45 GHZ written by Christine Marie Di Lapi and published by . This book was released on 1990 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conformal Array Antenna Theory and Design written by Lars Josefsson and published by John Wiley & Sons. This book was released on 2006-02-10 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first comprehensive treatment of conformal antenna arrays from an engineering perspective. While providing a thorough foundation in theory, the authors of this publication provide a wealth of hands-on instruction for practical analysis and design of conformal antenna arrays. Thus, you get the knowledge you need, alongside the practical know-how to design antennas that are integrated into such structures aircrafts or skyscrapers.

Download or read book Design and Theory of Slot Arrays Fed by Single ridge Rectangular Waveguide written by David Yonghoon Kim and published by . This book was released on 1985 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of and Design Procedure for Dual Circularly Polarized Waveguide Slot Arrays written by Lee M. Paulsen and published by . This book was released on 2006 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the past sixty years, waveguide slot radiator arrays have played a critical role in microwave radar and communication systems. They feature a well-characterized antenna element capable of direct integration into a low-loss feed structure with highly developed and inexpensive manufacturing processes. Waveguide slot radiators comprise some of the highest performance---in terms of side-lobe-level, efficiency, etc.---antenna arrays ever constructed.

Download or read book Newsletter written by and published by . This book was released on 2004 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microstrip Lines and Slotlines Third Edition written by Ramesh Garg and published by Artech House. This book was released on 2013-05-01 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the second edition of this book was published in 1996, planar transmission line technology has progressed considerably due to developments in ultrawideband (UWB) communications, imaging, and RFID applications. In addition, the simultaneous demands for compactness of wireless electronic devices while meeting improved performance requirements, necessitates increased use of computer-aided design, simulation, and analysis by microwave engineers. This book is written to help engineers successfully meet these challenges. Details include the development of governing equations, basis functions, Green’s function and typical results. More than 1200 equations supplement the text. Special attention is given to the use of simulation software in the design of complex devices and understanding the connection between data collected from simulation software and the actual design process. The book is primarily intended for microwave design engineers and R&D specialists who need to employ planar transmission lines in designing distributed circuits and antenna systems for a wide range of wireless applications. Advanced undergraduate and graduate students in electronics and telecommunication engineering will also welcome this addition to your library.

Download or read book Microstrip Antenna Design Handbook written by Ramesh Garg and published by Artech House. This book was released on 2001 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on Bahl and Bhartia's popular 1980 classic, Microstrip Antennas, this all new book provides the detail antenna engineers and designers need to design any type of microstrip antenna. After addressing essential microchip antenna theory, the authors highlight current design and engineering practices, emphasizing the most pressing issues in this area, including broadbanding, circular polarization, and active microstrip antennas in particular. Special design challenges, ranging from dual polarization, high bandwidth, and surface wave mitigation, to choosing the proper substrate, and shaping an antenna to achieve desired results are all covered.

Download or read book Higher Order FDTD Schemes for Waveguide and Antenna Structures written by Nikolaos V. Kantartzis and published by Morgan & Claypool Publishers. This book was released on 2006 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book provides a comprehensive and systematically organized coverage of higher order finite-difference time-domain or FDTD schemes, demonstrating their potential role as a powerful modeling tool in computational electromagnetics. Special emphasis is drawn on the analysis of contemporary waveguide and antenna structures."--BOOK JACKET.