768 research outputs found

    Accurate quantum transport modelling and epitaxial structure design of high-speed and high-power In0.53Ga0.47As/AlAs double-barrier resonant tunnelling diodes for 300-GHz oscillator sources

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    Terahertz (THz) wave technology is envisioned as an appealing and conceivable solution in the context of several potential high-impact applications, including sixth generation (6G) and beyond consumer-oriented ultra-broadband multi-gigabit wireless data-links, as well as highresolution imaging, radar, and spectroscopy apparatuses employable in biomedicine, industrial processes, security/defence, and material science. Despite the technological challenges posed by the THz gap, recent scientific advancements suggest the practical viability of THz systems. However, the development of transmitters (Tx) and receivers (Rx) based on compact semiconductor devices operating at THz frequencies is urgently demanded to meet the performance requirements calling from emerging THz applications. Although several are the promising candidates, including high-speed III-V transistors and photo-diodes, resonant tunnelling diode (RTD) technology offers a compact and high performance option in many practical scenarios. However, the main weakness of the technology is currently represented by the low output power capability of RTD THz Tx, which is mainly caused by the underdeveloped and non-optimal device, as well as circuit, design implementation approaches. Indeed, indium phosphide (InP) RTD devices can nowadays deliver only up to around 1 mW of radio-frequency (RF) power at around 300 GHz. In the context of THz wireless data-links, this severely impacts the Tx performance, limiting communication distance and data transfer capabilities which, at the current time, are of the order of few tens of gigabit per second below around 1 m. However, recent research studies suggest that several milliwatt of output power are required to achieve bit-rate capabilities of several tens of gigabits per second and beyond, and to reach several metres of communication distance in common operating conditions. Currently, the shortterm target is set to 5−10 mW of output power at around 300 GHz carrier waves, which would allow bit-rates in excess of 100 Gb/s, as well as wireless communications well above 5 m distance, in first-stage short-range scenarios. In order to reach it, maximisation of the RTD highfrequency RF power capability is of utmost importance. Despite that, reliable epitaxial structure design approaches, as well as accurate physical-based numerical simulation tools, aimed at RF power maximisation in the 300 GHz-band are lacking at the current time. This work aims at proposing practical solutions to address the aforementioned issues. First, a physical-based simulation methodology was developed to accurately and reliably simulate the static current-voltage (IV ) characteristic of indium gallium arsenide/aluminium arsenide (In-GaAs/AlAs) double-barrier RTD devices. The approach relies on the non-equilibrium Green’s function (NEGF) formalism implemented in Silvaco Atlas technology computer-aided design (TCAD) simulation package, requires low computational budget, and allows to correctly model In0.53Ga0.47As/AlAs RTD devices, which are pseudomorphically-grown on lattice-matched to InP substrates, and are commonly employed in oscillators working at around 300 GHz. By selecting the appropriate physical models, and by retrieving the correct materials parameters, together with a suitable discretisation of the associated heterostructure spatial domain through finite-elements, it is shown, by comparing simulation data with experimental results, that the developed numerical approach can reliably compute several quantities of interest that characterise the DC IV curve negative differential resistance (NDR) region, including peak current, peak voltage, and voltage swing, all of which are key parameters in RTD oscillator design. The demonstrated simulation approach was then used to study the impact of epitaxial structure design parameters, including those characterising the double-barrier quantum well, as well as emitter and collector regions, on the electrical properties of the RTD device. In particular, a comprehensive simulation analysis was conducted, and the retrieved output trends discussed based on the heterostructure band diagram, transmission coefficient energy spectrum, charge distribution, and DC current-density voltage (JV) curve. General design guidelines aimed at enhancing the RTD device maximum RF power gain capability are then deduced and discussed. To validate the proposed epitaxial design approach, an In0.53Ga0.47As/AlAs double-barrier RTD epitaxial structure providing several milliwatt of RF power was designed by employing the developed simulation methodology, and experimentally-investigated through the microfabrication of RTD devices and subsequent high-frequency characterisation up to 110 GHz. The analysis, which included fabrication optimisation, reveals an expected RF power performance of up to around 5 mW and 10 mW at 300 GHz for 25 μm2 and 49 μm2-large RTD devices, respectively, which is up to five times higher compared to the current state-of-the-art. Finally, in order to prove the practical employability of the proposed RTDs in oscillator circuits realised employing low-cost photo-lithography, both coplanar waveguide and microstrip inductive stubs are designed through a full three-dimensional electromagnetic simulation analysis. In summary, this work makes and important contribution to the rapidly evolving field of THz RTD technology, and demonstrates the practical feasibility of 300-GHz high-power RTD devices realisation, which will underpin the future development of Tx systems capable of the power levels required in the forthcoming THz applications

    Analysis and Design of Silicon based Integrated Circuits for Radio Frequency Identification and Ranging Systems at 24GHz and 60GHz Frequency Bands

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    This scientific research work presents the analysis and design of radio frequency (RF) integrated circuits (ICs) designed for two cooperative RF identification (RFID) proof of concept systems. The first system concept is based on localizable and sensor-enabled superregenerative transponders (SRTs) interrogated using a 24GHz linear frequency modulated continuous wave (LFMCW) secondary radar. The second system concept focuses on low power components for a 60GHz continuous wave (CW) integrated single antenna frontend for interrogating close range passive backscatter transponders (PBTs). In the 24GHz localizable SRT based system, a LFMCW interrogating radar sends a RF chirp signal to interrogate SRTs based on custom superregenerative amplifier (SRA) ICs. The SRTs receive the chirp and transmit it back with phase coherent amplification. The distance to the SRTs are then estimated using the round trip time of flight method. Joint data transfer from the SRT to the interrogator is enabled by a novel SRA quench frequency shift keying (SQ-FSK) based low data rate simplex communication. The SRTs are also designed to be roll invariant using bandwidth enhanced microstrip patch antennas. Theoretical analysis is done to derive expressions as a function of system parameters including the minimum SRA gain required for attaining a defined range and equations for the maximum number of symbols that can be transmitted in data transfer mode. Analysis of the dependency of quench pulse characteristics during data transfer shows that the duty cycle has to be varied while keeping the on-time constant to reduce ranging errors. Also the worsening of ranging precision at longer distances is predicted based on the non-idealities resulting from LFMCWchirp quantization due to SRT characteristics and is corroborated by system level measurements. In order to prove the system concept and study the semiconductor technology dependent factors, variants of 24GHz SRA ICs are designed in a 130nm silicon germanium (SiGe) bipolar complementary metal oxide technology (BiCMOS) and a partially depleted silicon on insulator (SOI) technology. Among the SRA ICs designed, the SiGe-BiCMOS ICs feature a novel quench pulse shaping concept to simultaneously improve the output power and minimum detectable input power. A direct antenna drive SRA IC based on a novel stacked transistor cross-coupled oscillator topology employing this concept exhibit one of the best reported combinations of minimum detected input power level of −100 dBm and output power level of 5.6 dBm, post wirebonding. The SiGe stacked transistor with base feedback capacitance topology employed in this design is analyzed to derive parameters including the SRA loop gain for design optimization. Other theoretical contributions include the analysis of the novel integrated quench pulse shaping circuit and formulas derived for output voltage swing taking bondwire losses into account. Another SiGe design variant is the buffered antenna drive SRA IC having a measured minimum detected input power level better than −80 dBm, and an output power level greater than 3.2 dBm after wirebonding. The two inputs and outputs of this IC also enables the design of roll invariant SRTs. Laboratory based ranging experiments done to test the concepts and theoretical considerations show a maximum measured distance of 77m while transferring data at the rate of 0.5 symbols per second using SQ-FSK. For distances less than 10m, the characterized accuracy is better than 11 cm and the precision is better than 2.4 cm. The combination of the maximum range, precision and accuracy are one of the best reported among similar works in literature to the author’s knowledge. In the 60GHz close range CW interrogator based system, the RF frontend transmits a continuous wave signal through the transmit path of a quasi circulator (QC) interfaced to an antenna to interrogate a PBT. The backscatter is received using the same antenna interfaced to the QC. The received signal is then amplified and downconverted for further processing. To prove this concept, two optimized QC ICs and a downconversion mixer IC are designed in a 22nm fully depleted SOI technology. The first QC is the transmission lines based QC which consumes a power of 5.4mW, operates at a frequency range from 56GHz to 64GHz and occupies an area of 0.49mm2. The transmit path loss is 5.7 dB, receive path gain is 2 dB and the tunable transmit path to receive path isolation is between 20 dB and 32 dB. The second QC is based on lumped elements, and operates in a relatively narrow bandwidth from 59.6GHz to 61.5GHz, has a gain of 8.5 dB and provides a tunable isolation better than 20 dB between the transmit and receive paths. This QC design also occupies a small area of 0.34mm² while consuming 13.2mW power. The downconversion is realized using a novel folded switching stage down conversion mixer (FSSDM) topology optimized to achieve one of the best reported combination of maximum voltage conversion gain of 21.5 dB, a factor of 2.5 higher than reported state-of-the-art results, and low power consumption of 5.25mW. The design also employs a unique back-gate tunable intermediate frequency output stage using which a gain tuning range of 5.5 dB is attained. Theoretical analysis of the FSSDM topology is performed and equations for the RF input stage transconductance, bandwidth, voltage conversion gain and gain tuning are derived. A feasibility study for the components of the 60GHz integrated single antenna interrogator frontend is also performed using PBTs to prove the system design concept.:1 Introduction 1 1.1 Motivation and Related Work . . . . . . . . . . . . . . . . . . . . . 1 1.2 Scope and Functional Specifications . . . . . . . . . . . . . . . . . 4 1.3 Objectives and Structure . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Features and Fundamentals of RFIDs and Superregenerative Amplifiers 9 2.1 RFID Transponder Technology . . . . . . . . . . . . . . . . . . . . 9 2.1.1 Chipless RFID Transponders . . . . . . . . . . . . . . . . . 10 2.1.2 Semiconductor based RFID Transponders . . . . . . . . . . 11 2.1.2.1 Passive Transponders . . . . . . . . . . . . . . . . 11 2.1.2.2 Active Transponders . . . . . . . . . . . . . . . . . 13 2.2 RFID Interrogator Architectures . . . . . . . . . . . . . . . . . . . 18 2.2.1 Interferometer based Interrogator . . . . . . . . . . . . . . . 19 2.2.2 Ultra-wideband Interrogator . . . . . . . . . . . . . . . . . . 20 2.2.3 Continuous Wave Interrogators . . . . . . . . . . . . . . . . 21 2.3 Coupling Dependent Range and Operating Frequencies . . . . . . . 25 2.4 RFID Ranging Techniques . . . . . . . . . . . . . . . . . . . . . . . 28 2.4.0.1 Received Signal Strength based Ranging . . . . . 28 2.4.0.2 Phase based Ranging . . . . . . . . . . . . . . . . 30 2.4.0.3 Time based Ranging . . . . . . . . . . . . . . . . . 30 2.5 Architecture Selection for Proof of Concept Systems . . . . . . . . 32 2.6 Superregenerative Amplifier (SRA) . . . . . . . . . . . . . . . . . . 35 2.6.1 Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2.6.2 Modes of Operation . . . . . . . . . . . . . . . . . . . . . . 42 2.6.3 Frequency Domain Characteristics . . . . . . . . . . . . . . 45 2.7 Semiconductor Technologies for RFIC Design . . . . . . . . . . . . 48 2.7.1 Silicon Germanium BiCMOS . . . . . . . . . . . . . . . . . 48 2.7.2 Silicon-on-Insulator . . . . . . . . . . . . . . . . . . . . . . . 48 3 24GHz Superregenerative Transponder based Identification and Rang- ing System 51 3.1 System Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3.1.1 SRT Identification and Ranging . . . . . . . . . . . . . . . . 51 3.1.2 Power Link Analysis . . . . . . . . . . . . . . . . . . . . . . 55 3.1.3 Non-idealities . . . . . . . . . . . . . . . . . . . . . . . . . . 59 3.1.4 SRA Quench Frequency Shift Keying for data transfer . . . 61 3.1.5 Knowledge Gained . . . . . . . . . . . . . . . . . . . . . . . 63 3.2 RFIC Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 3.2.1 Low Power Direct Antenna Drive CMOS SRA IC . . . . . . 66 3.2.1.1 Circuit analysis and design . . . . . . . . . . . . . 66 3.2.1.2 Characterization . . . . . . . . . . . . . . . . . . . 69 3.2.2 Direct Antenna Drive SiGe SRA ICs . . . . . . . . . . . . . 71 3.2.2.1 Stacked Transistor Cross-coupled Quenchable Oscillator . . . . . . . . . . . . . . . . . . . . . . . . 72 3.2.2.1.1 Resonator . . . . . . . . . . . . . . . . . . 72 3.2.2.1.2 Output Network . . . . . . . . . . . . . . 75 3.2.2.1.3 Stacked Transistor Cross-coupled Pair and Loop Gain . . . . . . . . . . . . . . . . . 77 3.2.2.2 Quench Waveform Design . . . . . . . . . . . . . . 85 3.2.2.3 Characterization . . . . . . . . . . . . . . . . . . . 89 3.2.3 Antenna Diversity SiGe SRA IC with Integrated Quench Pulse Shaping . . . . . . . . . . . . . . . . . . . . . . . . . . 91 3.2.3.1 Circuit Analysis and Design . . . . . . . . . . . . 91 3.2.3.1.1 Crosscoupled Pair and Sampling Current 94 3.2.3.1.2 Common Base Input Stage . . . . . . . . 95 3.2.3.1.3 Cascode Output Stage . . . . . . . . . . . 96 3.2.3.1.4 Quench Pulse Shaping Circuit . . . . . . 96 3.2.3.1.5 Power Gain . . . . . . . . . . . . . . . . . 99 3.2.3.2 Characterization . . . . . . . . . . . . . . . . . . . 102 3.2.4 Knowledge Gained . . . . . . . . . . . . . . . . . . . . . . . 103 3.3 Proof of Principle System Implementation . . . . . . . . . . . . . . 106 3.3.1 Superregenerative Transponders . . . . . . . . . . . . . . . 106 3.3.1.1 Bandwidth Enhanced Microstrip Patch Antennas 108 3.3.2 FMCW Radar Interrogator . . . . . . . . . . . . . . . . . . 114 3.3.3 Chirp Z-transform Based Data Analysis . . . . . . . . . . . 116 4 60GHz Single Antenna RFID Interrogator based Identification System 121 4.1 System Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 4.2 RFIC Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 4.2.1 Quasi-circulator ICs . . . . . . . . . . . . . . . . . . . . . . 125 4.2.1.1 Transmission Lines based Quasi-Circulator IC . . 126 4.2.1.2 Lumped Elements WPD based Quasi-Circulator . 130 4.2.1.3 Characterization . . . . . . . . . . . . . . . . . . . 134 4.2.1.4 Knowledge Gained . . . . . . . . . . . . . . . . . . 135 4.2.2 Folded Switching Stage Downconversion Mixer IC . . . . . 138 4.2.2.1 FSSDM Circuit Design . . . . . . . . . . . . . . . 138 4.2.2.2 Cascode Transconductance Stage . . . . . . . . . . 138 4.2.2.3 Folded Switching Stage with LC DC Feed . . . . . 142 4.2.2.4 LO Balun . . . . . . . . . . . . . . . . . . . . . . . 145 4.2.2.5 Backgate Tunable IF Stage and Offset Correction 146 4.2.2.6 Voltage Conversion Gain . . . . . . . . . . . . . . 147 4.2.2.7 Characterization . . . . . . . . . . . . . . . . . . . 150 4.2.2.8 Knowledge Gained . . . . . . . . . . . . . . . . . . 151 4.3 Proof of Principle System Implementation . . . . . . . . . . . . . . 154 5 Experimental Tests 157 5.1 24GHz System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 5.1.1 Ranging Experiments . . . . . . . . . . . . . . . . . . . . . 157 5.1.2 Roll Invariance Experiments . . . . . . . . . . . . . . . . . . 158 5.1.3 Joint Ranging and Data Transfer Experiments . . . . . . . 158 5.2 60GHz System Detection Experiments . . . . . . . . . . . . . . . . 165 6 Summary and Future Work 167 Appendices 171 A Derivation of Parameters for CB Amplifier with Base Feedback Capac- itance 173 B Definitions 177 C 24GHz Experiment Setups 179 D 60 GHz Experiment Setups 183 References 185 List of Original Publications 203 List of Abbreviations 207 List of Symbols 213 List of Figures 215 List of Tables 223 Curriculum Vitae 22

    Linear Predistortion-less MIMO Transmitters

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    Reliability Investigations of MOSFETs using RF Small Signal Characterization

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    Modern technology needs and advancements have introduced various new concepts such as Internet-of-Things, electric automotive, and Artificial intelligence. This implies an increased activity in the electronics domain of analog and high frequency. Silicon devices have emerged as a cost-effective solution for such diverse applications. As these silicon devices are pushed towards higher performance, there is a continuous need to improve fabrication, power efficiency, variability, and reliability. Often, a direct trade-off of higher performance is observed in the reliability of semiconductor devices. The acceleration-based methodologies used for reliability assessment are the adequate time-saving solution for the lifetime's extrapolation but come with uncertainty in accuracy. Thus, the efforts to improve the accuracy of reliability characterization methodologies run in parallel. This study highlights two goals that can be achieved by incorporating high-frequency characterization into the reliability characteristics. The first one is assessing high-frequency performance throughout the device's lifetime to facilitate an accurate description of device/circuit functionality for high-frequency applications. Secondly, to explore the potential of high-frequency characterization as the means of scanning reliability effects within devices. S-parameters served as the high-frequency device's response and mapped onto a small-signal model to analyze different components of a fully depleted silicon-on-insulator MOSFET. The studied devices are subjected to two important DC stress patterns, i.e., Bias temperature instability stress and hot carrier stress. The hot carrier stress, which inherently suffers from the self-heating effect, resulted in the transistor's geometry-dependent magnitudes of hot carrier degradation. It is shown that the incorporation of the thermal resistance model is mandatory for the investigation of hot carrier degradation. The property of direct translation of small-signal parameter degradation to DC parameter degradation is used to develop a new S-parameter based bias temperature instability characterization methodology. The changes in gate-related small-signal capacitances after hot carrier stress reveals a distinct signature due to local change of flat-band voltage. The measured effects of gate-related small-signal capacitances post-stress are validated through transient physics-based simulations in Sentaurus TCAD.:Abstract Symbols Acronyms 1 Introduction 2 Fundamentals 2.1 MOSFETs Scaling Trends and Challenges 2.1.1 Silicon on Insulator Technology 2.1.2 FDSOI Technology 2.2 Reliability of Semiconductor Devices 2.3 RF Reliability 2.4 MOSFET Degradation Mechanisms 2.4.1 Hot Carrier Degradation 2.4.2 Bias Temperature Instability 2.5 Self-heating 3 RF Characterization of fully-depleted Silicon on Insulator devices 3.1 Scattering Parameters 3.2 S-parameters Measurement Flow 3.2.1 Calibration 3.2.2 De-embedding 3.3 Small-Signal Model 3.3.1 Model Parameters Extraction 3.3.2 Transistor Figures of Merit 3.4 Characterization Results 4 Self-heating assessment in Multi-finger Devices 4.1 Self-heating Characterization Methodology 4.1.1 Output Conductance Frequency dependence 4.1.2 Temperature dependence of Drain Current 4.2 Thermal Resistance Behavior 4.2.1 Thermal Resistance Scaling with number of fingers 4.2.2 Thermal Resistance Scaling with finger spacing 4.2.3 Thermal Resistance Scaling with GateWidth 4.2.4 Thermal Resistance Scaling with Gate length 4.3 Thermal Resistance Model 4.4 Design for Thermal Resistance Optimization 5 Bias Temperature Instability Investigation 5.1 Impact of Bias Temperature Instability stress on Device Metrics 5.1.1 Experimental Details 5.1.2 DC Parameters Drift 5.1.3 RF Small-Signal Parameters Drift 5.2 S-parameter based on-the-fly Bias Temperature Instability Characterization Method 5.2.1 Measurement Methodology 5.2.2 Results and Discussion 6 Investigation of Hot-carrier Degradation 6.1 Impact of Hot-carrier stress on Device performance 6.1.1 DC Metrics Degradation 6.1.2 Impact on small-signal Parameters 6.2 Implications of Self-heating on Hot-carrier Degradation in n-MOSFETs 6.2.1 Inclusion of Thermal resistance in Hot-carrier Degradation modeling 6.2.2 Convolution of Bias Temperature Instability component in Hot-carrier Degradation 6.2.3 Effect of Source and Drain Placement in Multi-finger Layout 6.3 Vth turn-around effect in p-MOSFET 7 Deconvolution of Hot-carrier Degradation and Bias Temperature Instability using Scattering parameters 7.1 Small-Signal Parameter Signatures for Hot-carrier Degradation and Bias Temperature Instability 7.2 TCAD Dynamic Simulation of Defects 7.2.1 Fixed Charges 7.2.2 Interface Traps near Gate 7.2.3 Interface Traps near Spacer Region 7.2.4 Combination of Traps 7.2.5 Drain Series Resistance effect 7.2.6 DVth Correction 7.3 Empirical Modeling based deconvolution of Hot-carrier Degradation 8 Conclusion and Recommendations 8.1 General Conclusions 8.2 Recommendations for Future Work A Directly measured S-parameters and extracted Y-parameters B Device Dimensions for Thermal Resistance Modeling C Frequency response of hot-carrier degradation (HCD) D Localization Effect of Interface Traps Bibliograph

    Forecasting CO2 Sequestration with Enhanced Oil Recovery

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    The aim of carbon capture, utilization, and storage (CCUS) is to reduce the amount of CO2 released into the atmosphere and to mitigate its effects on climate change. Over the years, naturally occurring CO2 sources have been utilized in enhanced oil recovery (EOR) projects in the United States. This has presented an opportunity to supplement and gradually replace the high demand for natural CO2 sources with anthropogenic sources. There also exist incentives for operators to become involved in the storage of anthropogenic CO2 within partially depleted reservoirs, in addition to the incremental production oil revenues. These incentives include a wider availability of anthropogenic sources, the reduction of emissions to meet regulatory requirements, tax incentives in some jurisdictions, and favorable public relations. The United States Department of Energy has sponsored several Regional Carbon Sequestration Partnerships (RCSPs) through its Carbon Storage program which have conducted field demonstrations for both EOR and saline aquifer storage. Various research efforts have been made in the area of reservoir characterization, monitoring, verification and accounting, simulation, and risk assessment to ascertain long-term storage potential within the subject storage complex. This book is a collection of lessons learned through the RCSP program within the Southwest Region of the United States. The scope of the book includes site characterization, storage modeling, monitoring verification reporting (MRV), risk assessment and international case studies

    XVI Agricultural Science Congress 2023: Transformation of Agri-Food Systems for Achieving Sustainable Development Goals

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    The XVI Agricultural Science Congress being jointly organized by the National Academy of Agricultural Sciences (NAAS) and the Indian Council of Agricultural Research (ICAR) during 10-13 October 2023, at hotel Le Meridien, Kochi, is a mega event echoing the theme “Transformation of Agri-Food Systems for achieving Sustainable Development Goals”. ICAR-Central Marine Fisheries Research Institute takes great pride in hosting the XVI ASC, which will be the perfect point of convergence of academicians, researchers, students, farmers, fishers, traders, entrepreneurs, and other stakeholders involved in agri-production systems that ensure food and nutritional security for a burgeoning population. With impeding challenges like growing urbanization, increasing unemployment, growing population, increasing food demands, degradation of natural resources through human interference, climate change impacts and natural calamities, the challenges ahead for India to achieve the Sustainable Development Goals (SDGs) set out by the United Nations are many. The XVI ASC will provide an interface for dissemination of useful information across all sectors of stakeholders invested in developing India’s agri-food systems, not only to meet the SDGs, but also to ensure a stable structure on par with agri-food systems around the world. It is an honour to present this Book of Abstracts which is a compilation of a total of 668 abstracts that convey the results of R&D programs being done in India. The abstracts have been categorized under 10 major Themes – 1. Ensuring Food & Nutritional Security: Production, Consumption and Value addition; 2. Climate Action for Sustainable Agri-Food Systems; 3. Frontier Science and emerging Genetic Technologies: Genome, Breeding, Gene Editing; 4. Livestock-based Transformation of Food Systems; 5. Horticulture-based Transformation of Food Systems; 6. Aquaculture & Fisheries-based Transformation of Food Systems; 7. Nature-based Solutions for Sustainable AgriFood Systems; 8. Next Generation Technologies: Digital Agriculture, Precision Farming and AI-based Systems; 9. Policies and Institutions for Transforming Agri-Food Systems; 10. International Partnership for Research, Education and Development. This Book of Abstracts sets the stage for the mega event itself, which will see a flow of knowledge emanating from a zeal to transform and push India’s Agri-Food Systems to perform par excellence and achieve not only the SDGs of the UN but also to rise as a world leader in the sector. I thank and congratulate all the participants who have submitted abstracts for this mega event, and I also applaud the team that has strived hard to publish this Book of Abstracts ahead of the event. I wish all the delegates and participants a very vibrant and memorable time at the XVI ASC

    Reconfigurable Receiver Front-Ends for Advanced Telecommunication Technologies

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    The exponential growth of converging technologies, including augmented reality, autonomous vehicles, machine-to-machine and machine-to-human interactions, biomedical and environmental sensory systems, and artificial intelligence, is driving the need for robust infrastructural systems capable of handling vast data volumes between end users and service providers. This demand has prompted a significant evolution in wireless communication, with 5G and subsequent generations requiring exponentially improved spectral and energy efficiency compared to their predecessors. Achieving this entails intricate strategies such as advanced digital modulations, broader channel bandwidths, complex spectrum sharing, and carrier aggregation scenarios. A particularly challenging aspect arises in the form of non-contiguous aggregation of up to six carrier components across the frequency range 1 (FR1). This necessitates receiver front-ends to effectively reject out-of-band (OOB) interferences while maintaining high-performance in-band (IB) operation. Reconfigurability becomes pivotal in such dynamic environments, where frequency resource allocation, signal strength, and interference levels continuously change. Software-defined radios (SDRs) and cognitive radios (CRs) emerge as solutions, with direct RF-sampling receivers offering a suitable architecture in which the frequency translation is entirely performed in digital domain to avoid analog mixing issues. Moreover, direct RF- sampling receivers facilitate spectrum observation, which is crucial to identify free zones, and detect interferences. Acoustic and distributed filters offer impressive dynamic range and sharp roll off characteristics, but their bulkiness and lack of electronic adjustment capabilities limit their practicality. Active filters, on the other hand, present opportunities for integration in advanced CMOS technology, addressing size constraints and providing versatile programmability. However, concerns about power consumption, noise generation, and linearity in active filters require careful consideration.This thesis primarily focuses on the design and implementation of a low-voltage, low-power RFFE tailored for direct sampling receivers in 5G FR1 applications. The RFFE consists of a balun low-noise amplifier (LNA), a Q-enhanced filter, and a programmable gain amplifier (PGA). The balun-LNA employs noise cancellation, current reuse, and gm boosting for wideband gain and input impedance matching. Leveraging FD-SOI technology allows for programmable gain and linearity via body biasing. The LNA's operational state ranges between high-performance and high-tolerance modes, which are apt for sensitivityand blocking tests, respectively. The Q-enhanced filter adopts noise-cancelling, current-reuse, and programmable Gm-cells to realize a fourth-order response using two resonators. The fourth-order filter response is achieved by subtracting the individual response of these resonators. Compared to cascaded and magnetically coupled fourth-order filters, this technique maintains the large dynamic range of second-order resonators. Fabricated in 22-nm FD-SOI technology, the RFFE achieves 1%-40% fractional bandwidth (FBW) adjustability from 1.7 GHz to 6.4 GHz, 4.6 dB noise figure (NF) and an OOB third-order intermodulation intercept point (IIP3) of 22 dBm. Furthermore, concerning the implementation uncertainties and potential variations of temperature and supply voltage, design margins have been considered and a hybrid calibration scheme is introduced. A combination of on-chip and off-chip calibration based on noise response is employed to effectively adjust the quality factors, Gm-cells, and resonance frequencies, ensuring desired bandpass response. To optimize and accelerate the calibration process, a reinforcement learning (RL) agent is used.Anticipating future trends, the concept of the Q-enhanced filter extends to a multiple-mode filter for 6G upper mid-band applications. Covering the frequency range from 8 to 20 GHz, this RFFE can be configured as a fourth-order dual-band filter, two bandpass filters (BPFs) with an OOB notch, or a BPF with an IB notch. In cognitive radios, the filter’s transmission zeros can be positioned with respect to the carrier frequencies of interfering signals to yield over 50 dB blocker rejection

    Governing the High Seas : effective institutional arrangements for the conservation and sustainable use of marine biodiversity beyond national jurisdiction.

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    Forming almost two-thirds of the global ocean, the High Seas and seabed areas beyond national jurisdiction (ABNJ) support some of the highest levels of biodiversity on the planet. However, these vital areas are increasingly under threat from human and climate change-induced pressures. The current governance regime related to the conservation of marine biodiversity beyond national jurisdiction (BBNJ) is fragmented (in terms of institutional mandates, powers and resources) and characterised by significant gaps (in terms of species and geographical coverage). In response, the United Nations has negotiated an internationally legally binding instrument (ILBI) to protect the High Seas. A key aspect of the draft agreement is that that new instrument should “not undermine” existing bodies, instruments and frameworks, which raises key questions relating to interplay between the new ILBI and existing bodies. My research seeks to understand how the agreement can be effectively operationalised by analysing two related strands: (1) The need for the agreement to be effectively implemented by existing institutions, and (2) Due to the migratory nature of BBNJ and governance gaps, the need for existing institutions to work together effectively. I argue under (1) that four candidate conditions are likely to be important for implementation and deploy Qualitative Comparative Analysis (QCA) to identify one condition necessary for successful implementation (multi-party coordination) and three conditions (access to/management of data, multi-party coordination and adaptive management) which are sufficient to lead to a successful outcome. Under (2) a case study of the Northern Atlantic institutional regime is used to characterise and help explain the forces and factors influencing institutional interplay. Taken together, the two parts to the research generate insights into effective institutional arrangements for the future governance of BBNJ."This work was partially supported by the Robertson Postgraduate Scholarship Trust."--Fundin

    Technology, Science and Culture: A Global Vision, Volume IV

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