Satellite communications, Antennas (Electronics) -- Design and construction, Waveguides -- Design and construction, Sintering, 3D printing, and Computer-aided design

Keywords: additive manufacturing; fused filament fabrication; phase shifter; reconfigurable; selective laser sintering; waveguide Abstract This work presents the design and manufacturing of a K-band reconfigurable phase shifter completely implemented in waveguide technology for reduced insertion loss, good matching, and large phase shifting range. The device is based on the combination of a short slot coupler and two tunable reactive loads implemented as a section of short-circuited waveguide where an adjustable metallic post is inserted. Three prototypes of this design have been manufactured using different techniques (conventional computer numerical control machining, a low-cost fused filament fabrication technique and direct metal laser sintering) in order to assess its performance for different applications. The prototypes have been characterized experimentally and the achieved results are evaluated and compared. The proposed phase shifter, since it is fully developed in waveguide technology, eliminates the need of adding transitions to planar structures in order to integrate lumped components like pin diodes or varactors. Therefore, this device has a great potential in high-power beam steering phased arrays. Biographical information: Lucas Polo-Lopez received the BSc and MSc degrees in Telecommunication Engineering from the Universidad Autonoma de Madrid, Madrid, Spain in 2014 and 2016, respectively. Since 2015 he has been with the Radiofrequency Circuits, Antennas and Systems (RFCAS) group of this same university, where he works toward the PhD degree. His current research interests include the computer-aided design of horn antennas and passive waveguide devices, as well as the application of additive manufacturing techniques to the construction of waveguide devices. Jose L. Masa-Campos received the Master degree in 1999 and the PhD Degree in 2006, from the Universidad Politecnica de Madrid, Spain. From 1999 to 2003 he developed his professional activity in the R&D department of the company RYMSA with the design of base station antennas for mobile communications and satellite antennas. From 2002 to 2003 he directed the R&D department of RYMSA. From 2003 to 2007, he worked as Researcher for Universidad Politecnica de Madrid, and in 2005 he joined to Universidad Autonoma de Madrid as Associate Professor in the Radiofrequency Circuits, Antennas and Systems (RFCAS) group. His main current research interests are in active and passive planar array antennas. Jorge A. Ruiz-Cruz received the Ingeniero de Telecomunicacion degree and the PhD degree from the Universidad Politecnica de Madrid, Madrid, Spain, in 1999 and 2005, respectively. Since 2006, he has been with the Universidad Autonoma de Madrid, Madrid, where he became an Associate Professor in 2009. His current research interests include the computer-aided design of microwave passive devices and circuits (filters, multiplexers, and orthomodes). Byline: Lucas Polo-Lopez,Jose L. Masa-Campos,Jorge A. Ruiz-Cruz

Computer-Aided Design, Rapid Prototyping, New Technique, Models, Prototypes, Engineering -- Design and construction, and Computer industry -- Product information

Companies can produce a prototype from a computer-aided design (CAD) file within one or two days by using the services of one of the approximately 40 rapid prototyping (RP) service bureaus. The CAD system must interface with the RP equipment, the file format being particularly important. An STL file interfaces with most RP systems and can be created with a good CAD system. Alternatively, many software developers now offer STL translators. STL translators can be created only for solid-model CAD systems only, rather than for models that do not close. Surface models work only if they are designed to be watertight. Additionally, supports must be created for any cantilevers or other unsupported structures to develop a CAD model and it is often appropriate to allow the RP service bureau to create the supports themselves. Future alternatives to the STL format will allow users to create smooth, precise surfaces.

Directories, Stereolithography, Prototype, Three-Dimensional Graphics, Computer-Aided Design, Computer-Aided Manufacturing, Light Sculpting Inc. -- Product information, Helisys Inc. -- Product information, Light Sculpting LSI-1115MA (CAD/CAM system) -- Design and construction, Helisys LOM-2030 (CAD/CAM system) -- Design and construction, Quadrax Laser Technologies Mark 1000 Laser Modeling System (CAD/CAM system) -- Design and construction, Computer-aided manufacturing, Stereolithography -- Usage, and CAD-CAM systems industry -- Product information

There are several technologies for rapid prototyping, a manufacturing technique in which the prototype of a part is created in hours rather than weeks. Rapid prototyping systems use three dimensional computer-aided design (CAD) files, slicing the image into cross sections and constructing layers of solid material, bonding each to the one before it. 3D Systems Inc $385,000 SLA 190 uses stereolithography and focuses an ultraviolet light onto a liquid polymer. It can produce a 20X20X20 inch part in 3 hours. Stratasys Inc's $178,000 3D Modeler uses fused deposition modeling to produce a 12X12X12 inch part in under five hours. Helisys' $110,000 LOM-2030 uses laminated object modeling to create a 20X30X20 inch part in 15 to 30 hours. Light Sculpting Inc offers the $129,700 LSI-1115MA which produces an 11X11X15 inch part at 40 seconds per layer. Quadrax Laser Technologies Makes the $195,000 Mark 1000 Laser Modeling System which uses laser modeling to produce a 12X12X12 inch part in six to twenty-four hours.

Prototype, Computer-Aided Design, Circuit Design, Application-Specific Integrated Circuit, New Technique, Custom IC, Simulation, Verifier, Quickturn Systems Inc. -- Product information, and Quickturn Systems RPM Emulation System (Circuit designer) -- Design and construction

Circuit designers need a way to verify a total system completely before committing application-specific integrated circuits (ASICs) and custom chips to silicon to allow software and hardware to be developed concurrently. Field-programmable gate arrays (FPGAs) allow an implementation ideal for prototyping while not requiring the construction of silicon chips. Computer-aided prototyping (CAP) combines computer-aided engineering (CAE) translation and synthesis software with FPGA technology to produce hardware prototypes of chip designs automatically from netlists. Combining CAP with commercially available simulation tools allows systems designers to delay the decision to fabricate silicon chip prototypes until the latest possible time in the development cycle while still having a hardware prototype of the system running with software early in the cycle. Quickturn Systems' RPM Emulation System, the first commercial CAP system, is described.

Computer-aided design, Prototype, Command and Control Systems, Military, Logistics, Software Design, Automation, ADA, Code Generator, and Computer-aided design -- Usage

A Computer-Aided Prototyping System (CAPS) helps to automate the early stages of software design, supports system management and aids in controlling a system's evolution. The Prototype System Description Language (PDSL) integrates the tools in CAPS so that the designer can work from a real-time schedule and generate an executable Ada model automatically. This study works with a prototype having embedded software characteristics, hard real-time constraints, multiple and predefined hardware interfaces, and complex requirements. The Ada prototype processes tactical data from multiple interfaces in real time. CAPS, used with the Transportable Applications Environment Plus windowing package, generates the Ada code, which is then run on a Sun 3. This prototype currently serves as a test model for computer-aided software design research and in the investigation of deadlock detection and prevention at the design level.

Computer-Aided Design, Circuit Design, Prototype, New Technique, Technology, Integrated Systems, Real-Time System, California, University of (Berkeley), Research and Development, and University of California, Berkeley -- Research

The University of California, Berkeley, has developed the Hyper system that provides a completely integrated synthesis environment for real-time prototyping of datapath-intensive architectures, such as those used in high-performance, real-time systems in telecommunications, speech, video and image processing. Synthesis for real-time applications is defined as the hardware implementation with the least area, given an input computational graph, a number of real-time constraints and a hardware cell library. Hyper can generate a simulation model of the flow graph at any point, allowing the correctness of the executed operations to be verified and their effects on such performance parameters as the signal-to-noise ratio to be checked. The overall synthesis procedure in Hyper is implemented as a search process; new solutions are proposed by the system by executing such basic moves as adding or removing resources, changing the time allocation for different subgraphs in the algorithm, and applying an optimizing graph transformation.

Prototype, Circuit Design, Communications Circuits, Computer-Aided Design, CMOS, New Technique, Very-Large-Scale Integration, Bellcore -- Product information, and Mulga (CAD software) -- Design and construction

Circuit designers at Bell Communications Research (Bellcore) have used the Mulga symbolic design system since 1984 to design high-speed, research-prototype CMOS chips. The symbolic approach used in Mulga allows designers to create full-custom circuits offering high performance while providing the design productivity required to create research prototypes within a reasonable time. Chips designed using Mulga have reached speeds exceeding 240M-bps in a two-micron process, and test chips in a one-micron process have run at faster than 600M-bps. Mulga supports five processes and accommodates new sets of CMOS design rules easily, thus allowing designers to try various processes and compare them with little extra work as well as to evaluate cost/performance trade-offs quickly and simply. The advantages of the symbolic approach used in Mulga and use of the chip at Bellcore are discussed.

Computer-Aided Design, Circuit Design, Digital Signal Processor, New Technique, Software Packages, Packaging Density, Prototype, Testing, Debugging, Technology, General Electric Co. -- Product information, and GE Diodes (CAD system) -- Design and construction

General Electric Co's Diodes hardware prototype production system supports testing and debugging of digital-signal processor (DSP) designs as well as the fast and economical production of hardware prototypes. Diodes software partitions the DSP system into predefined function blocks, assembles it using advanced packaging technology, tests it and debugs it; it can be used as a standalone system or as part of a larger electronic environment. The algorithm is coded by the user in a high-level algorithmic language; the algorithm is translated into a structural specification by the synthesis software as a multichip module suitable for high-density interconnection (HDI) fabrication. HDI fabrication allows a prototype DSP module to be ready for testing in only a few days at a moderate cost compared to the cost of custom very-large-scale-integration (VLSI) design.

Learning strategies, Rapid prototyping, Computer-aided design, and Product life cycle

Byline: Maria Grazia Violante, Enrico Vezzetti Abstract Concept map are not a new phenomenon in engineering education and are nowadays used to enhance 'meaningful learning.' In literature a lot of works on the use of the concept maps in education exist, but not many within the 'interactive' context. This study contributes to expand the framework of research on the development of web-based 3D interactive concept maps. They incorporate web-based 3D interactive images that support the learning of abstract and difficult topics in Engineering drawing course, motivating the students and increasing their attention. The effects of different learning strategies (2D concept mapping vs. web-based 3D interactive concept mapping) on the learning outcomes and on the spatial ability are investigated. The results of this study shows that Web-based 3D interactive concept maps compensates spatial ability deficits, that is, helps students who have low spatial ability to build an effective mental representation of the learning content. [c] 2014 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:403-411, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21610 Biographical information: Maria Grazia Violante is currently assistant professor of Technical Drawing and Design Tools for Industrial Engineering at the Department of Management and Production Engineering of the Politecnico di Torino. From the same Politecnico she received her Master Degree in Industrial Engineering. In 2006 she was a visiting researcher at Wolfson School of Mechanical and Manufacturing Engineering- Loughborough University. She is author of technical papers on product design and development and interactive learning environments. Her research interest is focused on Product Lifecycle Management, Rapid Prototyping, Computer Aided Design, Virtual Reality, and E-learning. Enrico Vezzetti received the Master Degree in Industrial Engineering from the Politecnico di Torino in 1997, and the PhD Degree in Manufacturing Engineering from the University of Parma in 2001. In 1998 he was in the 3D Printing Laboratory of the Massachusetts Institute of Technology, USA. He is currently associate professor of Technical Drawing and Design Tools for Industrial Engineering at Department of Management and Production Engineering of the Politecnico di Torino. He is author of more than 80 technical papers on product design and development with specific attention on reverse engineering, rapid prototyping, collaborative design and virtual reality. His research interests include Computer Aided Design, Computer Aided Inspection, 3D Scanners and Virtual Reality.

Computer-aided design, Biomedical engineering, Online education, and Rapid prototyping

Byline: Maria Grazia Violante, Enrico Vezzetti ABSTRACT In a web-based learning environment, interactivity has been referred to as the most important element for successful e-learning. This article presents the production cycle of an interactive medical device, namely a virtual 3D electroencephalogram, and the study conducted to measure the students' satisfaction of the learning application based on Kano's quality model. The web-based interactive learning application introduces unique elements of interactivity with the learning content, specifically designed to train biomedical engineering students at the use of the medical device. The results of a post-deployment student survey suggest that the visual and interactive features embedded in the application have the potential to induce positive satisfaction of users. The proposed approach may serve as reference for the correct design of similar learning applications not only in the biomedical engineering context but also outside the realms of engineering sciences. [c] 2013 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:72-91, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21580 Biographical information: Maria Grazia Violante received her Master Degree in Industrial Engineering from Politecnico di Torino where she is currently an Assistant Professor of Technical Drawing and Design Tools for Industrial Engineering at the Department of Management and Production Engineering. In 2006 she was a visiting researcher at Wolfson School of Mechanical and Manufacturing Engineering- Loughborough University. She is author of technical papers on product design and development and interactive learning environments. Her research interest is focused on Rapid Prototyping, Computer Aided Design, Virtual Reality, E-learning. Enrico Vezzetti received his Master Degree in Industrial Engineering from the Politecnico di Torino in 1997, and his PhD Degree in Manufacturing Engineering from the University of Parma in 2001. In 1998 he was in the 3D Printing Laboratory of the Massachusetts Institute of Technology, USA. He is currently Associate Professor of Technical Drawing and Design Tools for Industrial Engineering at Department of Management and Production Engineering of the Politecnico di Torino. He is author of more than 80 technical papers on product design and development with specific attention on reverse engineering, rapid prototyping, collaborative design and virtual reality. His research interests include Computer Aided Design, Computer Aided Inspection, 3D Scanners and Virtual Reality.

Very-Large-Scale Integration, Computer-Aided Design, Software Engineering, Methods, Object-Oriented Data Bases, Utilization, Iteration, Requirements Analysis, Specifications, Ontologic Inc. -- Product information, and Vbase (Data base management system) -- Usage

The development of the Cbase computer-aided design (CAD) framework for very-large-scale integration (VLSI) circuit design at the University of Southern California demonstrates the value of a rapid prototyping strategy based on an object-oriented data base management system (OODBMS). A major problem in the development of large software systems is specifying and analyzing the potential users' requirements. The software engineer needs tools that enable the evolution of the system design in a manner that can accommodate incomplete initial requirements specifications as well as changing requirements. Rapid prototyping tools enable interactive development, refinement and analysis of multiple software system prototypes. An OODBMS facilitates the process by providing reusable code modules, powerful modeling capabilities and generic programming. Ontologic's commercial Vbase OODBMS package and the Massachusetts Institute of Technology X11 toolkit were employed to develop Cbase.

Prototype, Automation, Computer-Aided Software Engineering, Computer-Aided Design, Future of Computing, Software Design, and Software Quality

Computer-aided software prototyping and automation may help improve software productivity and reliability. Software prototyping helps customers understand and critique proposed systems while exploring alternative computer solutions that are time- and cost efficient. Speedy, accurate and inexpensive development becomes a necessity because prototypes are simple efficient models of future systems. They can also rely on different hardware or system software than the resulting program. Automation requires simple and clear mathematical models, and a standard set of abstract data types to form a machine representation of a standard prototyping language. The future prototyping tools may require a whole separate language combining the flexibility of an interpreted language with the capacity for selectively declaring compile-time constraints as consistent refinements. By formulating standards, the computer industry will help maintain a set of development standard tools that make software more reusable.