Design and analysis of an attenuator-based, four-channel, differential, 150 MHz, linear-in-dB VGA with sub-nanosecond delay dispersion for PET applications

Positron Emission Tomography (PET) is a medical imaging methodology based on the measurement of the concentrations of a positron-emitting radioisotope inside a three dimensional object. PET systems require hundreds of channels of high perfonnance detector readout electronics. The Phase I ASIC was developed in 1992 to reduce the cost, power consumption and complexity of PET systems and to improve reliability. The Phase I ASIC has been very successful and is a key component in thousands of commercial PET units currently in use

축차 비교형 아날로그-디지털 변환기의 성능 향상을 위한 기법에 대한 연구

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2016. 8. 김수환.This thesis is written about a performance enhancement technique for the successive-approximation-register analog-to-digital converter (SAR ADC). More specifically, it focuses on improving the resolution of the SAR ADC. The basic operation principles and the architecture of the conventional SAR ADC is examined. To gain insight on areas of improvement, a deeper look is taken at the building components of the SAR ADC. Design considerations of these components are discussed, along with the performance limiting factors in the resolution and bandwidth domains. Prior works which challenge these problems in order to improve the performance of the SAR ADC are presented. To design SAR ADCs, a high-level modeling is presented. This model includes various non-ideal effects that occur in the design and operation. Simulation examples are shown how the model is efficient and useful in the initial top-level designing of the SAR ADC. Then, the thesis proposes a technique that can enhance the resolution. The SAR ADC using integer-based capacitor digital-to-analog converter (CDAC) exploiting redundancy is presented. This technique improves the mismatch problem that arises with the widely used split-capacitor structure in the CDAC of the SAR ADC. Unlike prior works, there is no additional overhead of additional calibration circuits or reference voltages. A prototype SAR ADC which uses the integer-based CDAC exploiting redundancy is designed for automotive applications. Measurement results show a resolution level of 12 bits even without any form of calibration. Finally, the conclusion about the operation and effectiveness on the proposed technique is drawn.CHAPTER 1 INTRODUCTION 1 1.1 MOTIVATION 1 1.2 THESIS ORGANIZATION 5 CHAPTER 2 CONVENTIONAL SUCCESSIVE-APPROXIMATION-REGISTER ANALOG-TO-DIGITAL CONVERTERS 7 2.1 INTRODUCTION 7 2.2 OPERATION PRINCIPLE OF THE CONVENTIONAL SAR ADC 8 2.2.1. OVERVIEW OF THE OPERATION 8 2.2.2. SAMPLING PHASE 10 2.2.3. CONVERSION PHASE 11 2.3 STRUCTURE OF THE CONVENTIONAL SAR ADC 15 2.3.1. FULL STRUCTURE OF THE CONVENTIONAL SAR ADC 15 2.3.2. CAPACITOR DIGITAL-TO-ANALOG CONVERTER (CDAC) 17 2.3.3. COMPARATOR 21 2.3.4. CONTROL LOGIC 23 2.4 PERFORMANCE LIMITING FACTORS 24 2.4.1. RESOLUTION LIMITING FACTORS 24 2.4.2. OPERATION BANDWIDTH LIMITING FACTORS 28 2.5 PRIOR WORK 30 2.5.1. INTRODUCTION 30 2.5.2. SPLIT-CAPACITOR STRUCTURE OF THE CDAC 31 2.5.3. REDUNDANCY AND CDAC WEIGHT DISTRIBUTION 33 2.5.4. ASYNCHRONOUS CONTROL LOGIC 36 2.5.5. CALIBRATION TECHNIQUES 37 2.5.4. DOUBLE-SAMPLING TECHNIQUE FOR SAMPLING TIME REDUCTION 38 2.5.6. TWO-COMPARATOR ARCHITECTURE FOR COMPARATOR DECISION TIME REDUCTION 40 2.5.7. MAJORITY VOTING FOR RESOLUTION ENHANCEMENT 41 CHAPTER 3 MODELING OF THE SAR ADC 43 3.1 INTRODUCTION 43 3.2 WEIGHT DISTRIBUTION OF THE CAPACITOR DAC AND REDUNDANCY 44 3.3 SPLIT-CAPACITOR ARRAY TECHNIQUE 47 3.4 PARASITIC EFFECTS OF THE CAPACITOR DAC 48 3.5 MISMATCH MODEL OF THE CAPACITOR DAC 51 3.6 SETTLING ERROR OF THE DAC 53 3.7 COMPARATOR DECISION ERROR 58 3.8 DIGITAL ERROR CORRECTION 59 CHAPTER 4 SAR ADC WITH INTEGER-BASED SPLIT-CDAC EXPLOITING REDUNDANCY FOR AUTOMOTIVE APPLICATIONS 60 4.1 INTRODUCTION 60 4.2 MOTIVATION 61 4.3 PRIOR WORK ON RESOLVING THE SPLIT-CAPACITOR CDAC MISMATCH FOR THE SAR ADC 64 4.3.1. CONVENTIONAL SPLIT-CAPACITOR CDAC FOR THE SAR ADC 64 4.3.2. SPLITTING THE LAST STAGE OF THE LSB-SIDE OF THE CDAC 66 4.3.3. CALIBRATION OF THE NON-INTEGER MULTIPLE BRIDGE CAPACITOR 67 4.3.4. INTEGER-MULTIPLE BRIDGE CAPACITOR WITH LSB-SIDE CAPACITOR ARRAY CALIBRATION 68 4.3.5. OVERSIZED BRIDGE CAPACITOR WITH ADDITIONAL FRACTIONAL REFERENCE VOLTAGE 69 4.4 PROPOSED INTEGER-BASED CDAC EXPLOITING REDUNDANCY FOR THE SAR ADC 70 4.5 CIRCUIT DESIGN 72 4.5.1. PROPOSED INTEGER-BASED CDAC EXPLOITING REDUNDANCY FOR SAR ADC 72 4.5.2. COMPARATOR 74 4.5.3. CONTROL LOGIC 75 4.6 IMPLEMENTATION AND EXPERIMENTAL RESULTS 76 4.6.1. LAYOUT 76 4.6.2. MEASUREMENT RESULTS AND CONCLUSIONS 82 CHAPTER 5 CONCLUSION AND FUTURE WORK 86 5.1 CONCLUSION 86 5.2 FUTURE WORK 87 APPENDIX. SAR ADC USING THRESHOLD-CONFIGURING COMPARATOR FOR ULTRASOUND IMAGING SYSTEMS 89 BIBLIOGRAPHY 120Docto

System Level Modeling and Circuit Design for Low Voltage CMOS Equalizer for Coaxial Cable for Video Application

A new method of modeling coaxial cable frequency response with genetic algorithm was introduced. A system-level multi-stages adaptive equalizer model with QFB block was generated and tested with multiple cable models, pathological PRBS-23 data with data rate 1.5 GHz was used. This thesis also provided analysis of influences on output by using different parameters in simulations. Two adaptive equalizer circuits with different pre-amplifiers were implemented in GPDK 45 nm CMOS technology. Related simulations about adaptive ability, single stage compensation ability, and cascade stages compensation ability were completed. A tradeoff between output eye height and peak-to-peak jitter was discussed based on different simulations. Future work will be digital control circuit implementation, entire circuit fabrication, and testing

Smart optical imaging systems with automated electronics

In this dissertation, proposed and demonstrated are several novel smart electronically automated optical designs to efficiently solve existing real-world problems in the field of shape sensing and imaging. First half of the thesis proposes shape sensing techniques that use an Electronically Controlled Variable Focus Lens (ECVFL) within a smart optical design suitable for a wide range of applications including shape sensing and projection displays. The second part of this dissertation involves the use of the Digital Micromirror Device (DMD) deployed within several smart optical designs including an embedded laser beam profiler and a new camera idea which is inspired by the Telecommunication science field. Specifically, proposed and demonstrated is the design and implementation of the novel imaging device called Coded Access Optical Sensor (CAOS) where CAOS is able of operating with different application dependent working modes. Experimentally and successfully demonstrated for the first time are its use for coherent light laser imaging as well as for incoherent imaging of a high dynamic range white light scenario. It is also shown how its design can be further extended for multispectral and hyperspectral imaging applications

Spectral LADAR: Active Range-Resolved Imaging Spectroscopy

Imaging spectroscopy using ambient or thermally generated optical sources is a well developed technique for capturing two dimensional images with high per-pixel spectral resolution. The per-pixel spectral data is often a sufficient sampling of a material's backscatter spectrum to infer chemical properties of the constituent material to aid in substance identification. Separately, conventional LADAR sensors use quasi-monochromatic laser radiation to create three dimensional images of objects at high angular resolution, compared to RADAR. Advances in dispersion engineered photonic crystal fibers in recent years have made high spectral radiance optical supercontinuum sources practical, enabling this study of Spectral LADAR, a continuous polychromatic spectrum augmentation of conventional LADAR. This imaging concept, which combines multi-spectral and 3D sensing at a physical level, is demonstrated with 25 independent and parallel LADAR channels and generates point cloud images with three spatial dimensions and one spectral dimension. The independence of spectral bands is a key characteristic of Spectral LADAR. Each spectral band maintains a separate time waveform record, from which target parameters are estimated. Accordingly, the spectrum computed for each backscatter reflection is independently and unambiguously range unmixed from multiple target reflections that may arise from transmission of a single panchromatic pulse. This dissertation presents the theoretical background of Spectral LADAR, a shortwave infrared laboratory demonstrator system constructed as a proof-of-concept prototype, and the experimental results obtained by the prototype when imaging scenes at stand off ranges of 45 meters. The resultant point cloud voxels are spectrally classified into a number of material categories which enhances object and feature recognition. Experimental results demonstrate the physical level combination of active backscatter spectroscopy and range resolved sensing to produce images with a level of complexity, detail, and accuracy that is not obtainable with data-level registration and fusion of conventional imaging spectroscopy and LADAR. The capabilities of Spectral LADAR are expected to be useful in a range of applications, such as biomedical imaging and agriculture, but particularly when applied as a sensor in unmanned ground vehicle navigation. Applications to autonomous mobile robotics are the principal motivators of this study, and are specifically addressed

Study on the Terahertz Nondestructive Testing Method for Multi-chip Package Inspection using a Resonant Slit-type Probe with Rounded Matching Structure

This paper presents a terahertz (THz) non-destructive testing (NDT) method for multi-chip package (MCP) inspection. A resonant slit-type probe was used to obtain high resolution while using a source in the low Th frequency region for the Th inspection. However, the conventional resonant slit structure is difficult to manufacture due to the thin thickness of the slit, as well as the problem of increasing the change of the resonance frequency and the loss of reflection due to the thickness error of the slit. A resonant slit-type probe with a rounded matching structure was proposed to improve the coupling efficiency while improving the slit thickness problem in the Th region. The proposed probe can reduce the resonance frequency change according to the thickness error while maintaining the high coupling efficiency despite the increase of the slit thickness. It is possible to reduce the FWHM by more than 40% by using the proposed structure than the conventional resonant slit structure in the foreign object detection simulation using the slit probe. A probe with a resonant frequency of 205 GHz using the proposed structure was fabricated by electroforming and compared with VNA measurement results and CST MWS simulation results. From the measurement results, it was confirmed that the proposed probe has a simple structure and high coupling efficiency. Using the pulsed THz system, the transmission characteristics of the semiconductor chip according to the polarization direction were verified, and it was confirmed that the semiconductor inspection using the THz wave was possible. A continuous (CW) THz inspection system that can be applied to process inspection has been established. A THz transceiver module based on directional coupler and a THz transceiver module based on Magic-tee have been constructed. In addition, FPGA-based high-speed lock amplifiers have been built to improve detection rates for process inspections. Standard samples were used to verify the performance of the measurement system and probes. It was confirmed that the magic-based THz transceiver module is more suitable for defect detection. The probe structure fabricated using the proposed structure was able to detect defects of 100 µm, and the high - speed signal detection module was able to detect defects stably even at a sample moving speed of 1000 mm/s. In the semiconductor chip inspection, a lateral inspection method has been proposed because the conductivity of the semiconductor surface is high. The CST Microwave Studio simulation confirmed that side inspection enabled void detection. A lateral inspection system was constructed and a void of 500 ㎛ in diameter in the multi-chip package was detected. In addition, a simple contrast-transformed image filter is applied to the detected image so that defects in the laminated structure can be easily discriminated. As a result, it is confirmed that THz wave system using the proposed probe is a new inspection tool for detecting voids of multi-chip package.|본 논문에서는 다중 칩 패키지 검사를 위한 테라헤르츠 비파괴 검사 방법을 제시하였다. 테라헤르츠파 검사를 위해 저주파 영역의 테라헤르츠 광원을 사용하면서도 고해상도의 분해능을 얻기 위한 방법으로 공진형 슬릿 프로브를 적용하였다. 그러나 종래의 공진형 슬릿 구조는 슬릿 두께가 얇아 제작이 어려울 뿐만 아니라 슬릿 두께 오차에 따른 공진주파수 변화 및 반사손실(Return loss)이 증가하는 문제가 발생한다. 테라헤르츠파 영역에서의 슬릿 두께 문제를 개선하면서도 결합 효율을 높이기 위한 방법으로 둥근 정합 구조를 가진 공진형 슬릿 프로브를 제안하였다. 제안 된 프로브는 슬릿 두께의 증가에도 불구하고 높은 결합 효율을 유지함과 동시에 두께 오차에 따른 공진주파수 변화를 감소시킬 수 있다. 또한, 슬릿 프로브를 이용한 이물 검출 시뮬레이션에서 기존의 공진형 슬릿 구조보다 제안된 구조를 이용함으로써 반치폭 (FWHM)을 40% 이상 감소시킬 수 있었다. 제안된 구조를 적용한 공진 주파수가 205 GHz인 프로브를 전기도금 방식으로 제작하였으며, VNA 측정 결과와 CST MWS 시뮬레이션 결과와 비교하였다. 측정 결과로부터 제안 된 프로브가 구조적으로 간단하면서도 높은 결합 효율을 가짐을 확인하였다. 펄스형 테라헤르츠파 시스템을 구성, 반도체 칩의 편광 방향에 따른 투과 특성을 검증하여 테라헤르츠파를 이용한 반도체 검사가 가능함을 확인하였다. 공정 검사 적용이 가능한 연속형 테라헤르츠파 검사 시스템을 구축하였다. 방향성 커플러 (Directional coupler) 기반의 테라헤르츠파 송수신기 모듈과 매직 티 (Magic-tee) 기반의 테라헤르츠파 송수신기 모듈을 구성하였다. 또한, 공정 검사를 위한 검출 속도를 개선하기 위해 FPGA 기반의 고속 락인앰프 (lock-in amplifier)가 제작되었으며 반도체 표면의 도전성을 고려한 표준 샘플을 제작하여 측정 시스템과 프로브의 성능 검증을 위해 사용되었습니다. 매직 티 기반의 테라헤르츠파 트랜시버 모듈이 결함 검출에 더 적합함을 확인하였으며, 시스템을 이용한 프로브의 공간 분해능 검증 결과 100 µm의 공간 해상도을 가졌다. 또한, 고속 신호 처리 모듈을 이용하여 1000mm/s의 고속 이동 중에도 안정적으로 영상 검출이 가능함을 확인하였다. 반도체 칩을 이용한 검사에서는 반도체 표면의 높은 도전성으로 반사형 테라헤르츠파 시스템으로는 Void 검출이 어려워 측 방향(lateral) 검사 방식을 제안하였다. CST Microwave Studio 시뮬레이션을 통하여 측 방향 검사로 보이드 (Void) 검출이 가능함을 확인하였다. 측 방향 검사 시스템을 구성하였으며 적층 반도체 내의 직경 500 ㎛의 보이드를 검출하였다. 또한, 검출 영상에 간단한 콘트라스트 스트레칭 변환 영상 필터를 적용하여 프로브 구조에 따른 검출 신호를 개선함으로써 적층 구조 내의 결함을 쉽게 판별이 가능하도록 하였다. 결과적으로 제안된 프로브를 적용한 테라헤르츠파 시스템이 적층 반도체 내의 Void 검출을 위한 새로운 검사 방법임을 확인하였다.1. Introduction 1 1.1 Motivation 1 1.2 Outline 3 2. Background 5 2.1 Multi-chip package inspection technology and their Limit 5 2.1.1 Multi-chip package inspection using ultrasound 5 2.1.2 Multi-chip package inspection using infra-Red (IR) 6 2.1.3 Multi-chip package inspection using X-ray 8 2.2 THz inspection technology 9 2.2.1 Advantages of THz inspection technology 9 2.2.2 Issues in the THz inspection technology 12 2.2.3 THz technology for multi-chip package inspection 16 3. Resonant slit-type probe 19 3.1 Design of a resonant slit-type probe 19 3.1.1 Advantages of resonant slit-type probe 19 3.1.2 Theory of resonant slit-type probe 20 3.1.3 Resonant slit-type probe for THz wave 23 3.1.4 Matching structure of resonant slit-type probe 27 3.2 Resonant slit-type probe with rounded matching structure 27 3.2.1 Resonant slit-type probe with rounded matching structure 27 3.2.2 Fabrication of slit-type probe with rounded matching structure 34 3.2.3 Measurement of slit-type probe with rounded matching structure 37 4. Experimental setup 39 4.1 Components for CW THz imaging system 40 4.1.1 CW THz source 40 4.1.2 CW THz detector 41 4.1.3 FPGA based on fast lock-in amplifier 41 4.1.4 Fabrication of standard sample 48 4.2 CW THz Transceiver module for multi-chip package inspection 51 4.2.1 Design of THz transceiver module 51 4.2.2 Magic-tee based THz transceiver 56 4.2.3 Directional coupler based THz transceiver 56 5. Measurements and results 59 5.1 Verification of performance of THz imaging system 59 5.1.1 Measurement of spatial resolution of resonant slit-type probe with rounded matching structure 59 5.1.2 High-speed signal processing and image acquisition 60 5.2 Semiconductor chip inspection using pulsed THz wave 65 5.2.1 Inspection system using pulsed THz wave 65 5.2.2 Semiconductor chip inspection using pulsed THz wave 67 5.2.3 Transmission characteristics according to the polarization 72 5.3 Semiconductor chip inspection using CW THz wave 73 5.3.1 Semiconductor chip inspection using CW THz system based on directional Coupler 77 5.3.2 Semiconductor chip inspection using CW THz system based on magic-tee 80 5.3.3 Semiconductor chip inspection using CW THz wave 83 5.4 Multi-chip package inspection using CW THz wave 83 5.4.1 THz propagation in voids of multi-chip package in lateral inspection 83 5.4.2 Multi-chip package inspection using lateral inspection methode 85 5.4.3 Improvement of void image using image processing technique 89 5.4.4 Another application using slit-type probe (Food inspection) 93 6. Conclusion 99 Reference 103Docto

Millimeter-wave Communication and Radar Sensing — Opportunities, Challenges, and Solutions

With the development of communication and radar sensing technology, people are able to seek for a more convenient life and better experiences. The fifth generation (5G) mobile network provides high speed communication and internet services with a data rate up to several gigabit per second (Gbps). In addition, 5G offers great opportunities of emerging applications, for example, manufacture automation with the help of precise wireless sensing. For future communication and sensing systems, increasing capacity and accuracy is desired, which can be realized at millimeter-wave spectrum from 30 GHz to 300 GHz with several tens of GHz available bandwidth. Wavelength reduces at higher frequency, this implies more compact transceivers and antennas, and high sensing accuracy and imaging resolution. Challenges arise with these application opportunities when it comes to realizing prototype or demonstrators in practice. This thesis proposes some of the solutions addressing such challenges in a laboratory environment.High data rate millimeter-wave transmission experiments have been demonstrated with the help of advanced instrumentations. These demonstrations show the potential of transceiver chipsets. On the other hand, the real-time communication demonstrations are limited to either low modulation order signals or low symbol rate transmissions. The reason for that is the lack of commercially available high-speed analog-to-digital converters (ADCs); therefore, conventional digital synchronization methods are difficult to implement in real-time systems at very high data rates. In this thesis, two synchronous baseband receivers are proposed with carrier recovery subsystems which only require low-speed ADCs [A][B].Besides synchronization, high-frequency signal generation is also a challenge in millimeter-wave communications. The frequency divider is a critical component of a millimeter-wave frequency synthesizer. Having both wide locking range and high working frequencies is a challenge. In this thesis, a tunable delay gated ring oscillator topology is proposed for dual-mode operation and bandwidth extension [C]. Millimeter-wave radar offers advantages for high accuracy sensing. Traditional millimeter-wave radar with frequency-modulated continuous-wave (FMCW), or continuous-wave (CW), all have their disadvantages. Typically, the FMCW radar cannot share the spectrum with other FMCW radars.\ua0 With limited bandwidth, the number of FMCW radars that could coexist in the same area is limited. CW radars have a limited ambiguous distance of a wavelength. In this thesis, a phase-modulated radar with micrometer accuracy is presented [D]. It is applicable in a multi-radar scenario without occupying more bandwidth, and its ambiguous distance is also much larger than the CW radar. Orthogonal frequency-division multiplexing (OFDM) radar has similar properties. However, its traditional fast calculation method, fast Fourier transform (FFT), limits its measurement accuracy. In this thesis, an accuracy enhancement technique is introduced to increase the measurement accuracy up to the micrometer level [E]

Optical MEMS

Optical microelectromechanical systems (MEMS), microoptoelectromechanical systems (MOEMS), or optical microsystems are devices or systems that interact with light through actuation or sensing at a micro- or millimeter scale. Optical MEMS have had enormous commercial success in projectors, displays, and fiberoptic communications. The best-known example is Texas Instruments’ digital micromirror devices (DMDs). The development of optical MEMS was impeded seriously by the Telecom Bubble in 2000. Fortunately, DMDs grew their market size even in that economy downturn. Meanwhile, in the last one and half decade, the optical MEMS market has been slowly but steadily recovering. During this time, the major technological change was the shift of thin-film polysilicon microstructures to single-crystal–silicon microsructures. Especially in the last few years, cloud data centers are demanding large-port optical cross connects (OXCs) and autonomous driving looks for miniature LiDAR, and virtual reality/augmented reality (VR/AR) demands tiny optical scanners. This is a new wave of opportunities for optical MEMS. Furthermore, several research institutes around the world have been developing MOEMS devices for extreme applications (very fine tailoring of light beam in terms of phase, intensity, or wavelength) and/or extreme environments (vacuum, cryogenic temperatures) for many years. Accordingly, this Special Issue seeks to showcase research papers, short communications, and review articles that focus on (1) novel design, fabrication, control, and modeling of optical MEMS devices based on all kinds of actuation/sensing mechanisms; and (2) new developments of applying optical MEMS devices of any kind in consumer electronics, optical communications, industry, biology, medicine, agriculture, physics, astronomy, space, or defense

Desarrollo de un nuevo sistema de hipertermia de microondas para aplicaciones

[ENG]Microwave technology is now widely used in a variety of medical applications such as cancer treatment and diagnostics. This project describes the structure of a novel hyperthermia system for biomedical research. The software Ansoft HFSS was used to design a rectangular waveguide applicator. A closed-loop is presented in order to control the output power of the system by the temperature measured on the sample. Initial results from experimental testing are presented. In these results, it is shown that the water temperature can be increased from 21ºC to 40ºC in 12 minutes. Therefore, it has been tested that the system works properly. The next step would be to apply the system to melanoma cancer cells. [SPA]Ya existen tecnologías que implican el uso de microondas en una gran variedad de aplicaciones m édicas tales como el diagnóstico y el tratamiento del cáncer. Este proyecto describe la estructura de un nuevo sistema de hipertermia para ser usado en todo tipo de investigaciones biom édicas. El software Ansoft HFSS ha sido usado para diseñar una guía de onda rectangular que ser á el componente final al que se aplicar á nuestro sistema. Además, se dispone de un bucle cerrado en el propio sistema para poder controlar la potencia de salida en función de la temperatura medida en la muestra. Los resultados iniciales del experimento se han presentado en este documento. En estos resultados, se muestra que la temperatura del agua puede ser incrementada desde 21ºC hasta 40ºC en unos 12 minutos. Por lo tanto, se ha comprobado que el sistema funciona de forma adecuada. El siguiente paso ser a aplicar el sistema directamente sobre c elulas cancer genas.Escuela Técnica Superior de Ingeniería de TelecomunicaciónHeriot Watt UniversityUniversidad Politécnica de Cartagen