International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Remote, high speed, high explosive wave front monitoring requires very high bandwidth telemetry to allow transmission of diagnostic data before the explosion destroys the sensor system itself. The main motivation for this study is that no known existing implementation of this sort has been applied to realistic weapons environments. These facts have prompted the research and gathering of data that can be used to extrapolate towards finding the best modulation method for this application. In addition to research of similar existing analysis and testing operations, data was recently captured from a Joint Test Assembly (JTA) Air Launched Cruise Missile (ALCM) flight.

No description available.

This thesis reports the development of a wide-bandwidth high-sensitivity mode-decoupled MEMS gyroscope showing robustness against ambient pressure variations. The designed gyroscope is based on a novel 2 degrees of freedom (DoF) sense mode oscillator, which allows increasing the operation bandwidth to the amount required by tactical-grade and inertial-grade operations while reaching the mechanical sensitivity of near matched-mode vibratory gyroscopes. Thorough theoretical study and finite element simulations verify the high performance operation of the proposed 2 DoF sense mode oscillator design. The designed gyroscope is fabricated using the in-house developed silicon-on-glass (SOG) micromachining technology at METU Microelectronics (METU-MET) facilities. The fabricated gyroscope measures only 5.1 x 4.6 mm square. The drive mode oscillator of the gyroscope reaches quality factor of 8760 under 25 mTorr vacuum environment, owing to high quality single crystal silicon structural layer. The sense mode bandwidth is measured to reach 2.5 kHz at 40 V proof mass voltage. When the fabricated gyroscope is operated with a relatively wide bandwidth of 1kHz, measurements show a relatively high raw mechanical sensitivity of 131 uV/(deg/s). Fabricated gyroscope is hybrid connected to external closed-loop drive mode amplitude control and open-loop sense mode readout electronics developed at METU-MEMS research group, to form a complete angular rate measurement system (ARMS). The scale factor of the ARMS is measured to be 13.1 mV/(deg/s) with a maximum R square nonlinearity of 0.0006 % and a maximum percent deviation nonlinearity of 0.141 %, while the maximum deviation of the scale factor for large vacuum level variations between 40 mTorr to 500 mTorr is measured to be only 0.38 %. The bias stability and angle random walk of the gyroscope are measured to be 131 deg/h and 1.15 deg/ rooth, respectively. It is concluded that, the mechanical structure can be optimized to show its theoretical limits of sensitivity with improvements in fabrication tolerances. The proposed 2 DoF sense mode oscillator design shows the potential of tactical-grade operation, while demonstrating extreme immunity to ambient pressure variations, by utilizing an optimized mechanical structure and connecting the gyroscope to dedicated low-noise electronics.

Un Convertisseur Analogique-Numérique (CAN) pour les applications spatiales en astrophysique et cosmologie a été développé au cours de cette thèse. Cette catégorie de circuits demande des bandes passantes très larges, de très hautes fréquences d'échantillonnage et une faible résolution. L’architecture flash a été retenue pour sa rapidité et sa bande passante. La fréquence d’échantillonnage est de 8GHz. La technologie utilisée est la CMOS 65 nm de chez STMicroeletronics. La conception a été faite en deux phases. Une première qui a amené à un prototype d'un échantillonneur-bloqueur et une deuxième qui a amené au CAN. Les deux prototypes ont été caractérisés et à partir de ces résultats des perspectives d'amélioration pour les nouvelles implémentations ont été retrouvées.Pour atteindre l'objectif final du CAN multi-bits (6-bit sont visés) il a été décidé de dessiner une première version du CAN avec la moitié de la résolution initialement prévue (on passe de 6-bit à 3-bit). L'objectif est de nous permettre d’analyser le comportement des blocs fonctionnels intégrés et ensuite passer à une deuxième voire troisième version pour remplir le cahier des charges initial. / An Analog-to-Digital Converter (ADC) has been developed for astrophysical and cosmological applications. This class of circuits demands, especially in the millimeter wavelength domain, ultra wide bandwidths, ultra high sampling frequencies and a low resolution. The “flash” architecture has been chosen for its speed and bandwidth. This ADC samples at 8Gsps and it has been fabricated in 65nm CMOS technology from STMicroelectornics.The design has been done in two steps. The first was the prototype of a track-and-hold circuit. The second was the ADC. Both circuits have been characterized and from these results some perspectives for further improvements have been proposed.In order to achieve the final goal of the multi-bit ADC (6-bit resolution) we have decided to design a first prototype with half the final resolution, namely a 3-bit resolution ADC. Our idea was, with this first prototype, to conduct a first analysis of the behavior of the integrated functional blocks and, consequently, find the correct improvements required for the ADC final version.

Yes / In this work, a new prototype of the eight-element MIMO antenna system for 5G communications, internet of things, and networks has been proposed. This system is based on an H-shaped monopole antenna system that offers 200 MHz bandwidth ranges between 3.4-3.6GHz, and the isolation between any two elements is well below -12dB without using any decoupling structure. The proposed system is designed on a commercially available 0.8mm-thick FR4 substrate. One side of the chassis is used to place the radiating elements, while the copper from the other side is being removed to avoid short-circuiting with other components and devices. This also enables space for other systems, sub-systems, and components. A prototype is fabricated and excellent agreement is observed between the experimental and the computed results. It was found that ECC is 0.2 for any two radiating elements which is consistent with the desirable standards, and channel capacity is 38 bps/Hz which is 2.9 times higher than 4x4 MIMO configuration. In addition, single hand mode and dual hand mode analysis are conducted to understand the operation of the system under such operations and to identify losses and/or changes in the key performance parameters. Based on the results, the proposed antenna system will find its applications in modern 5G handheld devices and internet of things with healthcare and high rate delivery. Besides that, its design simplicity will make it applicable for mass production to be used in industrial demands.

No description available.

AC and DC impedances of switching power converters are used for the stability analysis of modern power electronics systems at three-phase AC and single-phase DC interfaces. Therefore, a small-signal characterization algorithm for switching power converter, which is based on FFT, will be presented and explained. The presented extraction algorithm is general and can be used to obtain other small-signal transfer functions of arbitrary power converter switching simulation models. Furthermore, FFT algorithm is improved by using cross power spectral density functions for identification, resulting in an algorithm, which is more noise immune. Both small-signal identification algorithms are validated in simulations, and CPSD algorithm is used in experimental measurement procedure. Several wide bandwidth injection signals, among which are chirp, multi-tone, pulse and white noise, are compared and theoretically analyzed. Several hardware examples are included in the analysis. The second part of the dissertation will focus on the modeling of small-signal input dq admittance of multi-pulse diode rectifiers, providing comparison between well-known averaged value models (AVMs), parametric averaged value models (PAVM), the switching simulation model and hardware measurements. Analytical expressions for all four admittances present in the dq matrix are derived and analyzed in depth, revealing the accuracy range of the averaged models. Furthermore, a hardware set-up is built, measured and modeled, showing that the switching simulation model captures nonlinear sideband effects accurately. In the end, a multi-pulse diode rectifier feeding a constant power load is analyzed with modified AVM and through detailed simulations of switching model, proving effectiveness of the proposed modifications. The third part describes implementation and design of a single-phase multi-level single-phase shunt current injection converter based on cascaded H-bridge topology. Special attention is given toward the selection of inductors and capacitors, trying to optimize the selected component values and fully utilize operating range of the converter. The proposed control is extensively treated, including inner current, outer voltage loop and voltage balancing loops. The designed converter is constructed and integrated with measurement system, providing experimental verification. The proposed multi-level single-phase converter is a natural solution for single-phase shunt current injection with the following properties: modular design, capacitor energy distribution, reactive element minimization, higher equivalent switching frequency, capability to inject higher frequency signals, suitable to perturb higher voltage power systems and capable of generating cleaner injection signals. Finally, a modular interleaved single-phase series voltage injection converter, consisting of multiple paralleled H-bridges is designed and presented. The decoupling control is proposed to regulate ac injection voltage, providing robust and reliable strategy for series voltage injection. The designed converter is simulated using detailed switching simulation model and excellent agreement between theory and simulation results are obtained. The presented control analysis treats different loads, examining robustness of the circuit to load variations. Simulation model and hardware prototype results verify the effectiveness of the proposed wide-bandwidth identification of small-signal dq impedances via single-phase injections. / Ph. D.

The ability to control the path a signal takes through microwave circuitry is crucial when designing RF systems. The component that allows for the control of the signal path is called a switch, and it is the microwave component that this thesis will focus on. Switches are widely used in the growing defense and space industries, both of which have strict requirements on their systems. This thesis aims to investigate four switch topologies and compare them to establish which topology is most suitable in high-performance systems where high isolation and wide bandwidths are essential parameters. The different topologies were simulated using Cadence AWR Microwave Studio to evaluate the parameters of interest. Built-in models for PIN diodes were employed to capture the nonlinear nature of the diodes and quantify the linearity of the switches. Measurements of PIN diodes using a spectrum analyzer and a vector network analyzer were used to confirm that the models of the PIN diode resembled the actual characteristics of PIN diodes. Out of the four topologies investigated, the series, shunt, series-shunt and double shunt, it was concluded that the series-shunt topology was most suitable for wideband multiple-throw switches. The double shunt topology was more suitable for SPST switches and narrowband SPDT switches. From this thesis, it will be possible to conclude which topology is most suitable for a particular need and what key design parameters will impact the switch’s performance. / Förmågan att styra vägen en signal tar genom mikrovågskretsar är en avgörande förmåga i konstruktionen av de flesta RF-system. Komponenten som tillåter styrning av signalvägen kallas en omkopplare och är den mikrovågskomponent som detta examensarbete kommer att fokusera på. RFomkopplare kan realiseras på många olika sätt och kan integreras i flera typer av vågledande strukturer såsom mikrostrips, striplines och vågledare. Omkopplingselementen kan realiseras på många sätt, med användning av transistorer och dioder är de mest etablerade sätten. Sådana omkopplare används i stor utsträckning inom försvars- och rymdindustrin som båda har strikta krav på dess komponenter. Avhandlingen syftar därför till att undersöka ett antal switchtopologier och jämföra dessa för att fastställa vilken topologi som är mest lämplig i högpresterande system där hög isolering och breda bandbredder är viktiga parametrar. De olika topologierna simulerades med hjälp av Cadence AWR Microwave Studio för att utvärdera parametrarna av intresse. Den inbyggda modellen för PIN-dioder användes också för att fånga diodernas olinjära natur för att kvantifiera omkopplarnas linjäritet. Mätningar av PIN-dioder med användning av en spektrumanalysator och en Nätverksanalysator gjordes för att bekräfta att modellerna av PIN-dioderna efterliknade PIN-diodernas faktiska beteende. Det fastslogs att series-shunt-topologin var mest lämpad för bredbandsomkopplare med flera utgångar. Dubbel-shunt-topologin var mer lämplig i SPSTomkopplare och i smalbandiga SPDT-omkopplare. Från detta examensarbete kommer det att vara möjligt att dra slutsatser kring vilken topologi som är mest lämplig för ett särskilt behov tillsammans med vilka designparametrar som kommer att påverka omkopplarens prestanda.

Yes / This paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. The aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. Concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. The radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. The open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. In this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation. / This work is partially supported by RTI2018-095499-B-C31, Funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE), and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424 and the fnancial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/1. / Research Development Fund Publication Prize Award winner, March 2020

The main objectives of this research are to investigate and design low profile antennas for mobile handsets applications using the balanced concept. These antennas are considered to cover a wide range of wireless standards such as: DCS (1710¿1880 MHz), PCS (1850¿1990 MHz), UMTS (1920¿2170 MHz), WLAN (2400¿2500 MHz and 5000 ¿ 5800 MHz) and UWB frequency bands. Various antennas are implemented based on built-in planar dipole with a folded arm structure. The performance of several designed antennas in terms of input return loss, radiation patterns, radiation efficiency and power gain are presented and several remarkable results are obtained. The measurements confirm the theoretical design concept and show reasonable agreement with computations. The stability performance of the proposed antenna is also evaluated by analysing the current distribution on the mobile phone ground plane. The specific absorption rate (SAR) performance of the antenna is also studied experimentally by measuring antenna near field exposure. The measurement results are correlated with the calculated ones. A new dual-band balanced antenna using coplanar waveguide structure is also proposed, discussed and tested; this is intended to eliminate the balanced feed network. The predicted and measured results show good agreement, confirming good impedance bandwidth characteristics and excellent dual-band performance. In addition, a hybrid method to model the human body interaction with a dual band balanced antenna structure covering the 2.4 GHz and 5.2 GHz bands is presented. Results for several test cases of antenna locations on the body are presented and discussed. The near and far fields were incorporated to provide a full understanding of the impact on human tissue. The cumulative distribution function of the radiation efficiency and absorbed power are also evaluated. / UK Engineering and Physical Sciences Research Council (EPSRC)