The analysis and modeling of fine pitch laminate interconnect in response to large energy fault transients

In embedded applications, the miniaturization of circuitry and functionality provides many benefits to both the producer and consumer. However, the benefits gained from miniaturization is not without penalty, as the environmental influences may be great enough to introduce system failures in new or different modes and effects;Of particular interest within this research is the effect of fault transients in reduced geometries of printed circuit card interconnect, commonly referred to as fine pitch laminate interconnect. Whereas larger geometries of conductor trace width and spacing may have been immune to circuit failure at a given fault input, the reduction of the trace geometry may introduce failures as the insulating effect of the dielectric is compromised to the point where arcing occurs;To address this concern, a circuit card was designed with fine pitch laminate features in microstrip, embedded microstrip, and stripline constructions. Various trace widths and separations were tested for structural integrity (presence of arcing or fusing) at voltage extremes defined in avionics standard. The specific trace widths in the test were 4 mils, 6 mils, 8 mils, and 12 mils, with the trace separation in each case equal to the trace widths. The results of the tests and methods to artificially improve the integrity of the interconnect are documented, providing a clear region of reliable operation to the designers and the engineering community;Finally, the construction of the interconnect and the results from the test were combined to create an empirical model for circuit analysis. Created for the Saber simulator, but readily adaptable to Spice, this model will describe high-speed operation of a propagating signal before breakdown, and uses data from the experiment to calculate threshold values for the arcing breakdown. The values for the breakdown voltages are correlated to the experimental data using statistical methods of weighted linear regression and hypothesis testing

Electromagnetic Interference and Compatibility

Recent progress in the fields of Electrical and Electronic Engineering has created new application scenarios and new Electromagnetic Compatibility (EMC) challenges, along with novel tools and methodologies to address them. This volume, which collects the contributions published in the “Electromagnetic Interference and Compatibility” Special Issue of MDPI Electronics, provides a vivid picture of current research trends and new developments in the rapidly evolving, broad area of EMC, including contributions on EMC issues in digital communications, power electronics, and analog integrated circuits and sensors, along with signal and power integrity and electromagnetic interference (EMI) suppression properties of materials

Scalable Control and Measurement of Gate-Defined Quantum Dot Systems

There is currently a worldwide effort towards the realisation of large-scale quantum computers that exploit quantum phenomena for information processing. While these computing systems could potentially redefine the technological landscape, harnessing quantum effects is challenging due to their inherently fragile nature and the experimentally demanding environments in which they arise. In order for quantum computation to be viable it is first necessary to demonstrate the operation of two-level quantum systems (qubits) which have long coherence times, can be quickly read out, and can be controlled with high fidelity. Focusing on these key requirements, this thesis presents four experiments towards scalable solid state quantum computing using gate-defined quantum dot devices based on gallium arsenide (GaAs) heterostructures. The first experiment investigates a phonon emission process that limits the charge coherence in GaAs and potentially complicates the microwave control of multi-qubit devices. We show that this microwave analogy to Raman spectroscopy can provide a means of detecting the unique phonon spectral density created by a nanoscale device. Experimental results are compared to a theoretical model based on a non-Markovian master equation and approaches to suppressing electron-phonon coupling are discussed. The second experiment demonstrates a technique involving in-situ gate electrodes coupled to lumped-element resonators to provide high-bandwidth dispersive read-out of the state of a double quantum dot. We characterise the charge sensitivity of this method in the few-electron regime and benchmark its performance against quantum point contact charge sensors. The third experiment implements a low-loss, chip-level frequency multiplexing scheme for the readout of scaled-up spin qubit arrays. Dispersive gate-sensing is realised in combination with charge detection based on two radio frequency quantum point contacts to perform multiplexed readout of a double quantum dot in the few-electron regime. Demonstration of a 10-channel multiplexing device is achieved and limitations in scaling spin qubit readout to large numbers using multiplexed channels discussed. The final experiment ties previously presented results together by realising a micro-architecture for controlling and reading out qubits during the execution of a quantum algorithm. The basic principles of this architecture are demonstrated via the manipulation of a semiconductor qubit using control pulses that are cryogenically routed using a high-electron mobility transistor switching matrix controlled by a field programmable gate array. Finally, several technical results are also presented including the development of printed circuit board solutions to allow the high-frequency measurement of nanoscale devices at cryogenic temperatures and the design of on-chip interconnects used to suppress electromagnetic crosstalk in high-density spin qubit device architectures

Design and analysis of highspeed electronics for electro optical payload of small satellites

With the increase in the resolution of the Earth observation satellites, the cameras on these satellites require more detectors to fulfil the swath need and also the image sensors have to operate at a very high-speed with the sensor electronics requiring faster clock rates and larger bandwidth. The sensor data handler has to transfer a large amount of data to the spacecraft in real time incorporating the outcomes of the signal integrity and power integrity analysis in the design. High-speed analysis is an important consideration for high resolution cameras and is often performed on the satellites. This research work aims towards presenting the design and analysis of high-speed electronics for small Earth observation satellites. A methodology will be defined for the designing of high-speed electronics that will involve both the pre-layout and post-layout designs for signal and power integrity analysis. The proposed research work also provides the pre-layout and post-layout signal integrity analysis of the high-speed electronics and interfaces and it will also validate the signal integrity performance of the module by comparing it with standard performance parameters. Similarly, we will perform a pre-layout and post-layout power integrity analysis of the high-speed electronics and interfaces and its effects on the power lines and power planes

Ultrasonic Positioning System for Electric Road System

Elonroad is a company that is looking into the possibility to charge electric vehicle on road. The conductor implemented on the driveway has a characteristic shape. The scope of this master thesis project is to identify the shape of the conductor and determine the relative position of the vehicle to the conductor using ultrasonic sensors. The goal is to have an update frequency of 30 Hz and a positioning error of maximum 2 cm. During the project a serial system containing 7 ultrasonic modules has been built. The sensor modules are mounted in an array and placed parallel to the road and perpendicular to the vehicles intended direction of travel. The ultrasonic modules are placed with a center distance of 10 cm on the array. A cross-correlation algorithm was implemented to determine the distance to the surface below each of the ultrasonic modules. The method to find the relative position of the vehicle uses a modified convolution algorithm which is proven to work under ideal circumstances. The distance measurement from the modules to ground can differ roughly +/-8 mm, this originates from the wavelength of the 40 kHz ultrasonic signal in air, the +/-8 mm error can, according to simulations give a positioning error of up to 5 cm. Simulations has indicated that +/-4 mm will give a positioning error less than, or equal to, 2 cm. The update frequency is assumed to be around 20 Hz, where the largest part is due to calculation time of the distance to ground. It can be lowered with more effective algorithms or with a more powerful microcontroller.Electric vehicles can charge their batteries on road by connecting to a conductor integrated in the roadway. In this specific case the integrated conductor consists in an elevated structure. This structures location relative the car needs to be tracked to ensure the car stays connected

An 8x1 Wideband Antenna Phased Array

In this project, we are trying to detect the direction of arrival of incoming radiation in the far-field region. To achieve this, we implemented a very flexible and low cost wideband 8x1 phased array antenna receiver system that performs digital beamforming. We designed and built ten aperture coupled patch antennas, radio-frequency (RF) front ends and intermediate-frequency (IF) stage blocks for each channel. Finally, we stored the data in the first-in-first-out (FIFO) memory placed on a Vertex6 FPGA on which we synthesized a microblaze microcontroller that uses SPI to control programmable RF devices and transfers data to the computer for further processing. Super-resolution direction of arrival and model order detection algorithms were implemented to perform the digital beamforming

Maximum crosstalk estimation and modeling of electromagnetic radiation from PCB/high-density connector interfaces

This dissertation explores two topics pertinent to electromagnetic compatibility research: maximum crosstalk estimation in weakly coupled transmission lines and modeling of electromagnetic radiation resulting from printed circuit board/high-density connector interfaces. Despite an ample supply of literature devoted to the study of crosstalk, little research has been performed to formulate maximum crosstalk estimates when signal lines are electrically long. Paper one illustrates a new maximum crosstalk estimate that is based on a mathematically rigorous, integral formulation, where the transmission lines can be lossy and in an inhomogeneous media. Paper two provides a thorough comparison and analysis of the newly derived maximum crosstalk estimates with an estimate derived by another author. In paper two the newly derived estimates in paper one are shown to be more robust because they can estimate the maximum crosstalk with fewer and less restrictive assumptions. One current industry challenge is the lack of robust printed circuit board connector models and methods to quantify radiation from these connectors. To address this challenge, a method is presented in paper three to quantify electromagnetic radiation using network parameters and power conservation, assuming the only losses at a printed circuit board/connector interface are due to radiation. Some of the radiating structures are identified and the radiation physics explored for the studied connector in paper three. Paper four expands upon the radiation modeling concepts in paper three by extending radiation characterization when material losses and multiple signals may be present at the printed circuit board/connector interface. The resulting radiated power characterization method enables robust deterministic and statistical analyses of the radiated power from printed circuit board connectors. Paper five shows the development of a statistical radiated power estimate based on the radiation characterization method presented in paper four. Maximum radiated power estimates are shown using the Markov and Chebyshev inequalities to predict a radiated power limit. A few maximum radiated power limits are proposed that depend on the amount of known information about the radiation characteristics of a printed circuit board connector --Abstract, page iv

A Compact Neutron Scatter Camera Using Optical Coded-Aperture Imaging

The detection and localization of fast neutron resources is an important capability for a number of nuclear security areas such as emergency response and arms control treaty verification. Neutron scatter cameras are one technology that can be used to accomplish this task, but current instruments tend to be large (meter scale) and not portable. Using optical coded-aperture imaging, fast plastic scintillator, and fast photodetectors that were sensitive to single photons, a portable neutron scatter camera was designed and simulated. The design was optimized, an experimental prototype was constructed, and neutron imaging was demonstrated with a tagged 252Cf source in the lab

FMCW Signals for Radar Imaging and Channel Sounding

A linear / stepped frequency modulated continuous wave (FMCW) signal has for a long time been used in radar and channel sounding. A novel FMCW waveform known as “Gated FMCW” signal is proposed in this thesis for the suppression of strong undesired signals in microwave radar applications, such as: through-the-wall, ground penetrating, and medical imaging radar. In these applications the crosstalk signal between antennas and the reflections form the early interface (wall, ground surface, or skin respectively) are much stronger in magnitude compared to the backscattered signal from the target. Consequently, if not suppressed they overshadow the target’s return making detection a difficult task. Moreover, these strong unwanted reflections limit the radar’s dynamic range and might saturate or block the receiver causing the reflection from actual targets (especially targets with low radar cross section) to appear as noise. The effectiveness of the proposed waveform as a suppression technique was investigated in various radar scenarios, through numerical simulations and experiments. Comparisons of the radar images obtained for the radar system operating with the standard linear FMCW signal and with the proposed Gated FMCW waveform are also made. In addition to the radar work the application of FMCW signals to radio propagation measurements and channel characterisation in the 60 GHz and 2-6 GHz frequency bands in indoor and outdoor environments is described. The data are used to predict the bit error rate performance of the in-house built measurement based channel simulator and the results are compared with the theoretical multipath channel simulator available in Matlab