Dipole-Moment-Based Reciprocity For Practical Desensitization Identification And Mitigation

Radio frequency interference can degrade the receiving sensitivity of antennas. The interference is usually caused by certain coupling structures, such as layouts without adequate grounding for the radio frequency signal return path. Those structures can be modeled as a set of equivalent dipole moments when they are electrically small. Herein, the dipole moment model-based coupling framework is applied to a practical cellphone design case to devise an engineering solution. The coupling framework incorporates dipole moments as radiation sources and a coupling model based on the reciprocity theorem. Unfortunately, near-field scan probes often lack access to all locations, owing to the complex phone platform structure. A combined measurement-simulation method is used to obtain the field quantities lacking direct access to measurements. The dipole-moment-based coupling framework helps estimate the couplings from different noise sources individually. Thus, the priority of solving for better layout designs can be determined according to the coupling estimations. Furthermore, the physics associated with the reconstructed dipole moment can provide insights and suggest possible mitigation methods. Several practical mitigation methods are discussed, including the suppression of the dominant noise source (reducing/cancelling the radiation or suppressing the specific noise spectrum) and the coupling path to the victim antenna

System efficient ESD design concept for soft failures

This research covers the topic of developing a systematic methodology of studying electrostatic discharge (ESD)-induced soft failures. ESD-induced soft failures (SF) are non-destructive disruptions of the functionality of an electronic system. The soft failure robustness of a USB3 Gen 1 interface is investigated, modeled, and improved. The injection is performed directly using transmission line pulser (TLP) with varying: pulse width, amplitude, polarity. Characterization provides data for failure thresholds and a SPICE circuit model that describes the transient voltage and current at the victim. Using the injected current, the likelihood of a SF is predicted. ESD protection by transient voltage suppressor (TVS) diodes is numerically simulated in several configurations. The results strongly suggest the viability of using well-established hard failure mitigation techniques for improving SF robustness, and the possibility of using numerical simulation for optimization purposes. A concept of soft failure system efficient ESD design (SF-SEED) is proposed and shown to be effective --Abstract, page iv

Metamaterial Absorbers for Mitigating Unintentional Radiated Emissions

Unintentional radiated emission spikes are one of the causes of failure in electromagnetic compliance tests of high-speed systems. In this thesis, a new absorber solution for mitigating such emissions is proposed using the concept of metamaterial structures. The absorber is placed inside the high-speed system shield box to match the low (almost zero) impedance of the metal walls to the wave impedance of unwanted radiations. As a result, waves reflected from the shield box are attenuated which eventually reduces the emissions leaked outside of the box. The effectiveness of the proposed solution is demonstrated through simulations and experimental evaluations of emissions from a 2D patch antenna array board representing a PCIe Gen 3 interface. The metamaterial absorber is implemented with PCB fabrication technology using resistive thin film layers. Two in-house radiation measurement setups are designed for this research to show the correlation between full-wave simulation results and the measurement of the fabricated prototype. The designed absorber reduces the emissions by more than 5 dB in the worst-case scenario of radiation source excitation. This provides a low-cost remedy for a marginally failing system to pass the EMC test without any change to the system board. For design and evaluation of the proposed metamaterial absorber solution, a clear methodology is presented in this thesis. The effects of the location of radiation sources, inter-component coupling, and shield box height on the design and performance of the proposed solution are investigated. In theoretical analysis, in addition to classical microwave cavity theory a new approach is employed by modeling the metamaterial absorber with a bulk material layer with complex permittivity and permeability. The bulk material design approach expedites theoretical evaluations and opens the door for further design explorations

Analog-Digital System Modeling for Electromagnetic Susceptibility Prediction

The thesis is focused on the noise susceptibility of communication networks. These analog-mixed signal systems operate in an electrically noisy environment, in presence of multiple equipments connected by means of long wiring. Every module communicates using a transceiver as an interface between the local digital signaling and the data transmission through the network. Hence, the performance of the IC transceiver when affected by disturbances is one of the main factors that guarantees the EM immunity of the whole equipment. The susceptibility to RF and transient disturbances is addressed at component level on a CAN transceiver as a test case, highlighting the IC features critical for noise immunity. A novel procedure is proposed for the IC modeling for mixed-signal immunity simulations of communication networks. The procedure is based on a gray-box approach, modeling IC ports with a physical circuit and the internal links with a behavioural block. The parameters are estimated from time and frequency domain measurements, allowing accurate and efficient reproduction of non-linear device switching behaviours. The effectiveness of the modeling process is verified by applying the proposed technique to a CAN transceiver, involved in a real immunity test on a data communication link. The obtained model is successfully implemented in a commercial solver to predict both the functional signals and the RF noise immunity at component level. The noise immunity at system level is then evaluated on a complete communication network, analyzing the results of several tests on a realistic CAN bus. After developing models for wires and injection probes, a noise immunity test in avionic environment is carried out in a simulation environment, observing good overall accuracy and efficiency

Development of a piezoelectric energy-harvesting sensor: from concept to reality

This study focuses on the development and integrated design over a 24-month period of a high efficiency energy-harvesting (EH) temperature sensor, based on piezoelectric materials, with applications for the sustainability of smart buildings, structures and infrastructures. The EH sensor, harvests the airflow inside Heating, Ventilation and Air Conditioning (HVAC) systems, using a piezoelectric component and an appropriate customizable aerodynamic fin that takes advantage of specific air flow effects, and is implemented for optimizing the energy consumption in buildings. The project was divided in several work-packages (some running in parallel) that cover different aspects of the device development. Some of them focus on engineering aspects (starting from the numerical modeling, then prototyping, and concluding with experimental testing). Other aspects focus on the sensor promotion (including the development of a business plan, the intellectual property rights, the final design and the go-to-market actions). Considering the multidisciplinary character of the project (involving knowledge from fields such as wind engineering, electrical engineering, industrial design, entrepreneurship), this study tries to provide an insight on the complex design issues that arise when such complex, sometimes conflicting and overlapping aspects have to be managed within strict deadlines. In doing so, the most important design and development aspects are critically presented

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Design Space Evaluation for Resonant and Hard-charged Switched Capacitor Converters

USB Power Delivery enables a fixed ratio converter to operate over a wider range of output voltages by varying the input voltage. Of the DC/DC step-down converters powered from this type of USB, the hard-charged Switched Capacitor circuit is of interest to industry for its potential high power density. However implementation can be limited by circuit efficiency. In fully resonant mode, the efficiency can be improved while also enabling current regulation. This expands the possible applications into battery chargers and eliminates the need for a two-stage converter.In this work, the trade-off in power loss and area between the hard-charged and fully resonant switched capacitor circuit is explored using a technique that remains agnostic to inductor technology. The loss model for each converter is presented as well as discussion on the restrained design space due to parasitics in the passive components. The results are validated experimentally using GaN-based prototype converters and the respective design spaces are analyzed

Design and Development of a Multi-Purpose Input Output Controller Board for the SPES Control System

This PhD work has been carried out at the Legnaro National Laboratories (LNL), one of the four national labs of the National Institute for Nuclear Physics (INFN). The mission of LNL is to perform research in the field of nuclear physics and nuclear astrophysics together with emerging technologies. Technological research and innovation are the key to promote excellence in science, to excite competitive industries and to establish a better society. The research activities concerning electronics and computer science are an essential base to develop the control system of the Selective Production of Exotic Species (SPES) project. Nowadays, SPES is the most important project commissioned at LNL and represents the future of the Lab. It is a second generation Isotope Separation On-Line (ISOL) radioactive ion beam facility intended for fundamental nuclear physics research as well as experimental applications in different fields of science, such as nuclear medicine; radio-pharmaceutical production for therapy and diagnostic. The design of the SPES control system demands innovative technologies to embed the control of several appliances with different requirements and performing different tasks spanning from data sharing and visualization, data acquisition and storage, networking, security and surveillance operations, beam transport and diagnostic. The real time applications and fast peripherals control commonly found in the distributed control network of particle accelerators are accompanied by the challenge of developing custom embedded systems. In this context, the proposed PhD work describes the design and development of a multi-purpose Input Output Controller (IOC) board capable of embedding the control of typical accelerator instrumentation involved in the automatic beam transport system foreseen for the SPES project. The idea behind this work is to extend the control reach to the single device level without losing in modularity and standardization. The outcome of the research work is a general purpose embedded computer that will be the base for standardizing the hardware layer of the frontend computers in the SPES distributed control system. The IOC board is a Computer-on-Module (COM) carrier board designed to host any COM Express type 6 module and is equipped with a Field Programmable Gate Array (FPGA) and user application specific I/O connection solutions not found in a desktop pc. All the generic pc functionalities are readily available in off-the-shelf modules and the result is a custom motherboard that bridges the gap between custom developments and commercial personal computers. The end user can deal with a general-purpose pc with a high level of hardware abstraction besides being able to exploit the on-board FPGA potentialities in terms of fast peripherals control and real time digital data processing. This document opens with an introductory chapter about the SPES project and its control system architecture and technology before to describe the IOC board design, prototyping, and characterization. The thesis ends describing the installation in the field of the IOC board which is the core of the new diagnostics data readout and signal processing system. The results of the tests performed under real beam conditions prove that the new hardware extends the current sensitivity to the pA range, addressing the SPES requirements, and prove that the IOC board is a reliable solution to standardize the control of several appliances in the SPES accelerators complex where it will be embedded into physical equipment, or in their proximity, and will control and monitor their operation replacing the legacy VME technology. The installation in the field of the IOC board represents a great personal reward and crowns these years of busy time during which I turned what was just an idea in 2014, into a working embedded computer today

Passive Balancing Battery Management System for Cal Poly Racing\u27s Formula SAE Electric Vehicle

This senior project aims to replace the current battery management system (BMS) on Cal Poly’s Formula SAE electric vehicle with a more versatile, advanced, and reliable system. A BMS manages a rechargeable battery by ensuring the battery device operator’s safety, protecting battery cell integrity, prolonging battery lifetime, maintaining functional design requirements, and sending optimal usage information to the application controller. Passive balancing maximizes a battery pack’s capacity by dissipating excess energy through heat to regulate cell state of charge