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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Dispositifs de protection contre les décharges électrostatiques pour les applications radio fréquences et millimétriques / Development of an ElectroStatic Discharges (ESD) protection circuit for millimeter-wave frequencies applications

Lim, Tek Fouy 28 May 2013 (has links)
Ces travaux s'inscrivent dans un contexte où les contraintes vis-à-vis des décharges électrostatiques sont de plus en plus fortes, les circuits de protection sont un problème récurrent pour les circuits fonctionnant à hautes fréquences. La capacité parasite des composants de protection limite fortement la transmission du signal et peut perturber fortement le fonctionnement normal d'un circuit. Les travaux présentés dans ce mémoire font suite à une volonté de fournir aux concepteurs de circuits fonctionnant aux fréquences millimétriques un circuit de protection robuste présentant de faibles pertes en transmission, avec des dimensions très petites et fonctionnant sur une très large bande de fréquences, allant du courant continu à 100 GHz. Pour cela, une étude approfondie des lignes de transmission et des composants de protection a été réalisée à l'aide de simulations électromagnétiques et de circuits. Placés et fragmentées le long de ces lignes de transmission, les composants de protection ont été optimisés afin de perturber le moins possible la transmission du signal, tout en gardant une forte robustesse face aux décharges électrostatiques. Cette stratégie de protection a été réalisée et validée en technologies CMOS avancées par des mesures fréquentielles, électriques et de courant de fuite. / Advanced CMOS technologies provide an easier way to realize radio-frequency integrated circuits (RFICs). However, the lithography dimension shrink make electrostatic discharges (ESD) issues become more significant. Specific ESD protection devices are embedded in RFICs to avoid any damage. Unfortunately, ESD protections parasitic capacitance limits the operating bandwidth of RFICs. ESD protection size dimensions are also an issue for the protection of RFICs, in order to avoid a significant increase in production costs. This work focuses on a broadband ESD solution (DC-100 GHz) able to be implemented in an I/O pad to protect RFICs in advanced CMOS technologies. Thanks to the signal transmission properties of coplanar / microstrip lines, a broadband ESD solution is achieved by implementing ESD components under a transmission line. The silicon proved structure is broadband; it can be used in any RF circuits and fulfill ESD target. The physical dimensions also enable easy on-chip integration.
122

Design and analysis of key components for manufacturable and low-power CMOS millimeter-wave receiver front end

Hsin, Shih-Chieh 02 November 2012 (has links)
The objective of this dissertation is to develop key components of a CMOS heterodyne millimeter-wave receiver front end. Robust designs are necessary to overcome PVT variations as well as modeling inaccuracies, while with minimum power consumption overhead to facilitate low-power radio for portable applications. Heterodyne receiver topology is adopted because of its robust performances at millimeter-wave frequencies. Device models for both passive and active devices are developed and used in the circuit designs in this dissertation. Two low-noise amplifiers (LNAs) are developed in this dissertation. The first LNA features a proposed temperature-compensation biasing technique, which confines the gain variation within 5 dB for temperature variation from -5 to 85 Celsius degree. The measured gain and NF are 21 and 6.5 dB, respectively, for 49-mW power dissipation. The second LNA reveals a design technique to tolerate a low-accuracy model at millimeter-wave frequencies. Both LNAs provide full coverage of the FCC 60-GHz band (57-64 GHz). For the frequency generation circuits, both the IF QVCO and mm-wave VCO are investigated. The inherent bimodal oscillation of QVCOs is analyzed and, for the first time, a systematic measurement technique is proposed to intentionally control the oscillation mode. This technique is further utilized to extend the tuning range of the QVCO, which possesses dual tuning curves without penalty on phase noise. The measurement results of a 13-GHz QVCO in 90-nm CMOS reveals a 21.4% tuning range for continuously tuning from 11.7 to 14.5 GHz. The measured phase noise is -108 dBc/Hz at 1 MHz offset with a core power consumption of 10.8 mW. A millimeter-wave VCO is designed and fabricated in 65-nm CMOS. The VCO is fully characterized under voltage stress to examine the hot-carrier injection effects affecting the performance of a millimeter-wave VCO. The 41.6-47.4 GHz VCO is further integrated into a millimeter-wave down converter. The power-hungry buffer amplifiers are neglected by proper floor planning. Conversion loss of 1.4 dB is obtained with total power consumption of 72.5 mW. Lastly, a power management system consisting of low-dropout (LDO) regulators is designed and integrated in a 90-nm CMOS millimeter-wave transceiver to provide stable and low-noise supply voltages. Voltage variation issues are alleviated by the LDOs.
123

Integrated Antennas and Active Beamformers Technology for mm-Wave Phased-Array Systems

Biglarbegian, Behzad 26 March 2012 (has links)
In this thesis, based on the indoor channel measurements and ray-tracing modeling for the indoor mm-wave wireless communications, the challenges of the design of the radio in this band is studied. Considering the recently developed standards such as IEEE 802.15.3c, ECMA and WiGig at 60 GHz, the link budget of the system design for different classes of operation is done and the requirement for the antenna and other RF sections are extracted. Based on radiation characteristics of mm-wave and the fundamental limits of low-cost Silicon technology, it is shown that phased-array is the ultimate solution for the radio and physical layer of the mobile millimeter wave multi-Gb/s wireless networks. Different phased-array configurations are studied and a low-cost single-receiver array architecture with RF phase-shifting is proposed. A systematic approach to the analysis of the overall noise-figure of the proposed architecture is presented and the component technical requirements are derived for the system level specifications. The proposed on-chip antennas and antenna-in-packages for various applications are designed and verified by the measurement results. The design of patch antennas on the low-cost RT/Duroid substrate and the slot antennas on the IPD technologies as well as the compact on-chip slot DRA antenna are explained in the antenna design section. The design of reflective-type phase shifters in CMOS and MEMS technologies is explained. Finally, the design details of two developed 60 GHz integrated phased-arrays in CMOS technology are discussed. Front-end circuit blocks such as LNA, continuous passive reflective-type phase shifters, power combiner and variable gain amplifiers are investigated, designed and developed for a 60 GHz phased-array radio in CMOS technology. In the first design, the two-element CMOS phased-array front-ends based on passive phase shifting architecture is proposed and developed. In the second phased-array, the recently developed on-chip dielectric resonator antenna in our group in lower frequency is scaled and integrated with the front-end.
124

Computational spectral microscopy and compressive millimeter-wave holography

Fernandez, Christy Ann January 2010 (has links)
<p>This dissertation describes three computational sensors. The first sensor is a scanning multi-spectral aperture-coded microscope containing a coded aperture spectrometer that is vertically scanned through a microscope intermediate image plane. The spectrometer aperture-code spatially encodes the object spectral data and nonnegative</p> <p>least squares inversion combined with a series of reconfigured two-dimensional (2D spatial-spectral) scanned measurements enables three-dimensional (3D) (x, y, &#955) object estimation. The second sensor is a coded aperture snapshot spectral imager that employs a compressive optical architecture to record a spectrally filtered projection</p> <p>of a 3D object data cube onto a 2D detector array. Two nonlinear and adapted TV-minimization schemes are presented for 3D (x,y,&#955) object estimation from a 2D compressed snapshot. Both sensors are interfaced to laboratory-grade microscopes and</p> <p>applied to fluorescence microscopy. The third sensor is a millimeter-wave holographic imaging system that is used to study the impact of 2D compressive measurement on 3D (x,y,z) data estimation. Holography is a natural compressive encoder since a 3D</p> <p>parabolic slice of the object band volume is recorded onto a 2D planar surface. An adapted nonlinear TV-minimization algorithm is used for 3D tomographic estimation from a 2D and a sparse 2D hologram composite. This strategy aims to reduce scan time costs associated with millimeter-wave image acquisition using a single pixel receiver.</p> / Dissertation
125

Highly Integrated Three Dimensional Millimeter-Wave Passive Front-End Architectures Using System-on-Package (SOP) Technologies for Broadband Telecommunications and Multimedia/Sensing Applications

Lee, Jong-Hoon 05 July 2007 (has links)
The objective of the proposed research is to present a compact system-on-package (SOP)-based passive front-end solution for millimeter-wave wireless communication/sensor applications, that consists of fully integrated three dimensional (3D) cavity filters/duplexers and antenna. The presented concept is applied to the design, fabrication and testing of V-band transceiver front-end modules using multilayer low temperature co-fired (LTCC) technology. The millimeter-wave front-end module is the foundation of 60 GHz (V-band) wireless systems for short-range multimedia applications, such as high-speed internet access, video streaming and content download. Its integration poses stringent challenges in terms of high performance, large number of embedded passive components, low power consumption, low interference between integrated components and compactness. To overcome these major challenges, a high level of integration of embedded passive functions using low-cost and high-performance materials that can be laminated in 3D, such as the multilayer LTCC, is significantly critical in the module-level design. In this work, various compact and high-performance passive building blocks have been developed in both microstrip and cavity configurations and their integration, enabling a complete passives integration solution for 3D low-cost wireless millimeter-wave front-end modules. It is worthy to note that most of the designs implemented comes away with novel ideas and is presented as the first extensive state-of-art components, entirely validated by measured data at 60 GHz bands.
126

Fully integrated cmos phase shifter/vco for mimo/ism application

Tavakoli Hosseinabadi, Ahmad Reza 15 May 2009 (has links)
A fully integrated CMOS 0 – 900 phase shifter in 0.18um TSMC technology is presented. With the increasing use of wireless systems in GHz range, there is high demand for integrated phase shifters in phased arrays and MIMO on chip systems. Integrated phase shifters have quite a high number of integrated inductors which consume a lot of area and introduce a huge amount of loss which make them impractical for on chip applications. Also tuning the phase shift is another concern which seems difficult with use of passive elements for integrated applications. This work is presents a new method for implementing phase shifters using only active CMOS elements which dramatically reduce the occupied area and make the tuning feasible. Also a fully integrated millimeter-wave VCO is implemented using the same technology. This VCO can be part of a 24 GHz frequency synthesizer for 24 GHz ISM band transceivers. The 24 GHz ISM band is the unlicensed band and available for commercial communication and automotive radar use, which is becoming attractive for high bandwidth data rate.
127

Zero-level Packaging Of Microwave And Millimeter-wave Mems Components

Comart, Ilker 01 September 2010 (has links) (PDF)
This thesis presents realization of two shunt, capacitive contact RF MEMS switches and two RF MEMS SPDT switches for microwave and millimeter-wave applications, two zero-level package structures for RF MEMS switches and development trials of a BCB based zero level packaging process cycle. Two shunt, capacitive contact RF MEMS switches for 26 GHz and 12 GHz operating frequencies are designed, fabricated and consistencies between fabricated devices and designs are shown through RF measurements. For the switch design at 26 GHz and at the operating frequency, return loss in the upstate is measured to be 27.61 dB, insertion loss and isolation in the downstate is measured to be 0.21 dB and 27.16 dB, respectively. For the switch design at 12 GHz and at the operating frequency, return loss in the upstate is measured to be 38.69 dB, insertion loss and isolation in the downstate is measured to be 0.05 dB and 25.84 dB, respectively. Quite accurate circuit models have been obtained for both of the RF MEMS switches. Two RF MEMS SPDT switches, which utilize the shunt, capacitive contact switches as building blocks are designed through circuit simulations. These two designs are fabricated and their RF measurements have been completed. It is shown from circuit model simulations that, the performances of the fabricated devices and desired responses corresponded to each other. For the SPDT switch design at 26 GHz, return loss at the input port is measured to be 12 dB and insertion loss is measured to be 1.24 dB. For the SPDT switch design at 12 GHz, return loss at the input port is measured to be 5.6 dB and insertion loss is measured to be 0.49 dB. The reason behind the unexpectedly bad performances has been investigated and discovered. The bad performances were due to a common mistake in the layouts of both SPDT switches. These mistakes are corrected in the circuit models and expected performances are obtained. Two different zero-level package structures which use high-resistive Si wafers have been suggested and required design changes have been made on the RF MEMS shunt, capacitive contact switches and SPDT switches in order to minimize the package effects. For this purpose polygonal CPW transitions have been designed and integrated into the designs, followed by the necessary tunings in the switch structures for which EM and circuit simulations are utilized. For the suggested package structures to be produced, two possible process cycles have been studied. One of the process flows was based on KOH anisotropic Si etching and the other one was based on DRIE (Deep Reactive Ion Etching). Great progress has been achieved in the latter process cycle, however this process cycle still needs some more study and it could not be completed in the time required for this thesis study.
128

Multi-gigabit low-power wireless CMOS demodulator

Yeh, David Alexander 30 June 2010 (has links)
This dissertation presents system and circuit development of the low-power multi-gigabit CMOS demodulator using analog and mixed demodulation techniques. In addition, critical building blocks of the low-power analog quadrature front-ends are designed and implemented using 90 nm CMOS with a targeted compatibility to the traditional demodulator architecture. It exhibits an IF-to-baseband conversion gain of 25 dB with 1.8 GHz of baseband bandwidth and a dynamic range of 23 dB while consuming only 46 mW from a 1 V supply voltage. Several different demodulators using analog signal processor (ASP) are implemented: (1) an ultra-low power non-coherent ASK demodulator is measured to demodulate a maximum speed of 3 Gbps while consuming 32 mW from 1.8 V supply; (2) a mere addition of 7.5 mW to the aforementioned analog quadrature front-end enables a maximum speed of 2.5 Gbps non-coherent ASK demodulation with an improved minimum sensitivity of -38 dBm; (3) a robust coherent BPSK demodulator is shown to achieve a maximum speed of 3.5 Gbps based on the same analog quadrature front-end with only additional 7 mW. Furthermore, an innovative seamless handover mechanism between ASP and PLL is designed and implemented to improve the frequency acquisition time of the coherent BPSK demodulator. These demodulator designs have been proven to be feasible and are integrated in a 60 GHz wireless receiver. The system has been realized in a product prototype and used to stream HD video as well as transfer large multi-media files at multi-gigabit speed.
129

The centimeter- and millimeter-wavelength ammonia absorption spectra under jovian conditions

Devaraj, Kiruthika 13 October 2011 (has links)
Accurate knowledge of the centimeter- and millimeter-wavelength absorptivity of ammonia is necessary for the interpretation of the emission spectra of the jovian planets. The objective of this research has been to advance the understanding of the centimeter- and millimeter-wavelength opacity spectra of ammonia under jovian conditions using a combination of laboratory measurements and theoretical formulations. As part of this research, over 1000 laboratory measurements of the 2-4 mm-wavelength properties of ammonia under simulated upper and middle tropospheric conditions of the jovian planets, and approximately 1200 laboratory measurements of the 5-20 cm-wavelength properties of ammonia under simulated deep tropospheric conditions of the jovian planets have been performed. Using these and pre-existing measurements, a consistent mathematical formalism has been developed to reconcile the centimeter- and millimeter-wavelength opacity spectra of ammonia. This formalism can be used to estimate the opacity of ammonia in a hydrogen/helium atmosphere in the centimeter-wavelength range at pressures up to 100 bar and temperatures in the 200 to 500 K range and in the millimeter-wavelength range at pressures up to 3 bar and temperatures in the 200 to 300 K range. In addition, a preliminary investigation of the influence of water vapor on the centimeter-wavelength ammonia absorptivity spectra has been conducted. This work addresses the areas of high-sensitivity centimeter- and millimeter-wavelength laboratory measurements, and planetary science, and contributes to the body of knowledge that provides clues into the origin of our solar system. The laboratory measurements and the model developed as part of this doctoral research work can be used for interpreting the emission spectra of jovian atmospheres obtained from ground-based and spacecraft-based observations. The results of the high-pressure ammonia opacity measurements will also be used to support the interpretation of the microwave radiometer (MWR) measurements on board the NASA Juno spacecraft at Jupiter.
130

Signal Processing for mmWave MIMO Radar

Faus García, Óscar January 2015 (has links)
This thesis addresses the design study, implementation and analysis of signal processing algorithms for a 79 GHz millimeter-wave Phase Modulated Continuous Wave (PMCW) Multi Input Multi Output (MIMO) short range radar; performed in IMEC research institute (Leuven, Belgium). The radar system targets high resolution performance with low power consumption in order to integrate a full MIMO radar transceiver with digital processor and antennas in a compact package featuring a size of 1 cm2. Achieving such radar system characteristics requires the exploitation of a highly demanding digital architecture with signal processing gain and high range, speed and angle resolutions. The improved resolution and detection capabilities will be achieved by performing signal processing algorithms on the reflected waveform. The digital front-end implements parallel range gate processing with a bank of correlators that perform: pulse compression, coherent accumulation to further increase Signal to Noise Ratio (SNR) and N-point FFT to extract the Doppler information. The use of MIMO is proposed implementing a code domain technique in the PMCW waveform, the Outer Hadamard Code MIMO. This concept makes use of a unique sequence for all the transmitting antennas that is rendered by an outer sequence to ensure the orthogonality of the transmitted waveforms. The outer code makes use of the good cross-correlation properties of the Hadamard sequences and the waveform uses sequences that exhibit perfect auto-correlation profile, the Almost Perfect Autocorrelation Sequences (APAS). The MIMO implementation results in higher angular resolution and extra processing gain. The use of beamforming techniques in the radar allows the angle estimation of the detected targets; using rough and fine beamforming that provides with coarse and precise Angle of Arrival (AoA) estimation in an early and late stage respectively. A Constant False Alarm Rate (CFAR) processing stage is implemented in the stage of the system where higher signal processing gain is achieved. This algorithm allows the variation of the CFAR parameters and analyzes the detections in order to improve the probability of detection (Pd) while decreasing the probability of false alarm (Pfa). A series of simulations with different scenarios and variable parameters are set in order to analyze the performance of the system. The simulations analyze the gain achieved in each stage and their outcomes show an impressive processing gain that can reach SNR improvements as high as 77 dB for a small virtual array while keeping the Pfa low with the CFAR adjustment. The use of bigger arrays demonstrates the possibility to enable clear detections for low Radar Cross Section (RCS) targets in far distances of the unambiguous range. The use of beamforming shows interference reduction improvement as the beam widths narrow with the increasing number of virtual array antennas. These results have been achieved while keeping the system design parameters to a range resolution of 7.5 cm for a maximum range of 37.5 meters with speed resolution of 0.2 m/s and a maximum detectable speed of 12.66 m/s. The outcomes support the good performance of the signal processing techniques implemented and the benefits in applying them in a SoC mmWave MIMO radar.

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