Millimeter-Wave and Terahertz Transceivers in SiGe BiCMOS Technologies

This invited paper reviews the progress of silicon–germanium (SiGe) bipolar-complementary metal–oxide–semiconductor (BiCMOS) technology-based integrated circuits (ICs) during the last two decades. Focus is set on various transceiver (TRX) realizations in the millimeter-wave range from 60 GHz and at terahertz (THz) frequencies above 300 GHz. This article discusses the development of SiGe technologies and ICs with the latter focusing on the commercially most important applications of radar and beyond 5G wireless communications. A variety of examples ranging from 77-GHz automotive radar to THz sensing as well as the beginnings of 60-GHz wireless communication up to THz chipsets for 100-Gb/s data transmission are recapitulated. This article closes with an outlook on emerging fields of research for future advancement of SiGe TRX performance

Concepts for Short Range Millimeter-wave Miniaturized Radar Systems with Built-in Self-Test

This work explores short-range millimeter wave radar systems, with emphasis on miniaturization and overall system cost reduction. The designing and implementation processes, starting from the system level design considerations and characterization of the individual components to final implementation of the proposed architecture are described briefly. Several D-band radar systems are developed and their functionality and performances are demonstrated

Millimeter-Wave Super-Regenerative Receivers for Wireless Communication and Radar

Today’s world is becoming increasingly automated and interconnected with billions of smart devices coming online, leading to a steep rise in energy consumption from small microelectronics. This coincides with an urgent push to transform global energy production to green energies, causing disruptions and energy shortages, and making the case for efficient energy use ever more pressing. Two major areas where high growth is expected are the fields of wireless communication and radar sensors. Millimeter-wave frequency bands are planned for fifth-generation (5G) and sixth-generation (6G) cellular communication standards, as well as automotive frequency-modulated continuous wave (FMCW) radar systems for driving assistance and automation. Fast silicon-based technologies enable these advances by operating at high maximum frequencies, such as the silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) technologies. However, even the fastest transistors suffer from low and energy expensive gains at millimeter-wave frequencies. Rather than incremental improvements in circuit efficiency using conventional approaches, a disruptive revolution for green microelectronics could be enabled by exploring the low-power benefits of the super-regenerative receiver for some applications. The super-regenerative receiver uses a regenerative oscillator circuit to increase the gain by positive feedback, through coupling energy from the output back into the input. Careful bias and control of the circuit enables a very large gain from a small number of transistors and a very low energy dissipation. Thus, the super-regenerative oscillator could be used to replace amplifier circuits in high data rate wireless communication systems, or as active reflectors to increase the range of FMCW radar systems, greatly reducing the power consumption. The work in this thesis presents fundamental scientific research into the topic of energy-efficient millimeter-wave super-regenerative receivers for use in civilian wireless communication and radar applications. This research work covers the theory, analysis, and simulations, all the way up to the proof of concept, hardware realization, and experimental characterization. Analysis and modeling of regenerative oscillator circuits is presented and used to improve the understanding of the circuit operation, as well as design goals according to the specific application needs. Integrated circuits are investigated and characterized as a proof of concept for a high data rate wireless communication system operating between 140–220 GHz, and an automotive radar system operating at 60 GHz. Amplitude and phase regeneration capabilities for complex modulation are investigated, and principles for spectrum characterization are derived. The circuits are designed and fabricated in a 130 nm SiGe HBT technology, combining bipolar and complementary metal-oxide semiconductor (BiCMOS) transistors. To prove the feasibility of the research concepts, the work achieves a wireless communication link at 16 Gbit/s over 20 cm distance with quadrature amplitude modulation (QAM), which is a world record for the highest data rate ever reported in super-regenerative circuits. This was powered by a super-regenerative oscillator circuit operating at 180 GHz and providing 58 dB of gain. Energy efficiency is also considerably high, drawing 8.8 mW of dc power consumption, which corresponds to a highly efficient 0.6 pJ/bit. Packaging and module integration innovations were implemented for the system experiments, and additional broadband circuits were investigated to generate custom quench waveforms to further enhance the data rate. For radar active reflectors, a regenerative gain of 80 dB is achieved at 60 GHz from a single circuit, which is the best in its frequency range, despite a low dc power consumption of 25 mW

Développement d'une architecture innovante de récepteur radar à 77 GHz et démonstration en CMOS 28 nm FDSOI

Grâce à sa capacité à détecter des cibles éloignées malgré une mauvaise visibilité, le radar automobile à 77 GHz joue un rôle important dans l'aide à la conduite. L'utilisation des fréquences millimétriques offre une bonne résolution et une importante capacité d'intégration des circuits. C'est aussi un défi car il faut satisfaire un cahier des charges exigeant sur le bruit et la linéarité du récepteur. Les technologies SiGe BiCMOS ont été les premières utilisées pour la conception de récepteurs radar à 77 GHz. De bons résultats ont été obtenus en se basant sur des architectures utilisant des mélangeurs actifs. Cependant l'utilisation des technologie BiCMOS se traduisait par une consommation élevée, une faible capacité d'intégration et des coûts de production importants. Récemment, l'intégration des procédés CMOS menant à l'augmentation des fréquences de transition rend ces technologies plus attractives pour les applications nécessitant un faible coût et la cointégration de plusieurs fonctions au sein d'une même puce. La littérature sur les récepteurs radars en technologie CMOS à 77 GHz montre que les architectures inspirées par les technologies BiCMOS ne sont pas pertinentes pour cette application. Le but de cette thèse et de montrer que l'utilisation de techniques propres aux technologie CMOS comme l'échantillonnage et l'utilisation de portes logiques permet d'obtenir de très bonnes performances. Dans ce travail, deux nouvelles architectures de récepteurs radars basées sur le principe d'échantillonnage sont proposées. La première architecture est basée sur un mélangeur passif échantillonné qui permet d'obtenir un très bon compromis bruit/linéarité. La seconde exploite les propriétés des mélangeurs sous-échantillonnés afin utiliser une fréquence d'OL trois fois inférieure à la fréquence RF offrant ainsi de très intéressantes simplifications au niveau de la chaîne de distribution du signal d'OL du récepteur. Le contexte de cette étude est expliqué dans le 1er chapitre qui présente les exigences de conception liées à l'application radar et fourni une analyse de l'état de l'art des récepteurs à 77 GHZ. Le chapitre suivant décrit le principe de fonctionnement et l'implémentation d'un mélangeur échantillonné à 77 GHz en technologie CMOS 28- nm FDSOI. Une topologie de mélangeur sous-échantillonné utilisant une fréquence d'OL de 26 GHz pour convertir des signaux RF autour de 77 GHz est ensuite détaillée dans le chapitre 3. Le chapitre 4 conclut cette étude en détaillant l'intégration des mélangeurs étudiés dans les chapitres précédents avec un amplificateur faible bruit dans différents récepteurs radars. Ces architectures de récepteurs basées sur l'échantillonnage sont ensuite comparées entre elles et avec l'état de l'art montrant ainsi leurs avantages et inconvénients. Les résultats de cette comparaison confirment l'intérêt des techniques d'échantillonnage pour la conversion de fréquence dans le cadre de l'application radar.With its ability to detect distant targets under harsh visibility conditions, the 77 GHz automotive radar plays a key role in driving safety. Using mm-wave frequencies allow a good range resolution, a better circuit integration and a wide modulation bandwidth. This is also a challenge for circuit designers who must fulfill stringent requirements especially on the receiver front-end. First 77 GHz radar receivers were manufactured with SiGe BiCMOS processes benefiting from the high transition frequency and high breakdown voltage of Hetero-junction Bipolar Transistors (HBT). Good results have been achieved with active-mixer-based architectures, but these technologies suffer from high power consumptions, limited integration capacity and large production cost. More recently, the scaling down of CMOS processes (coming together with the increase of the transition frequency of the transistors) makes CMOS a good candidate for 77 GHz circuit design, especially when cost target requires single chip solutions. The literature related to CMOS radar receivers highlights that receivers based on BiCMOS architectures generally show poor performances. The aim of this work is to demonstrate that using CMOS specific technics such as sampling and the use of high-speed digital gates should enhance the performance of the receivers. In this work, two innovative radar receiver architectures based on the sampling principle are proposed. The first one shows that this principle can be extended to millimeter wave frequencies to benefit from a very good noise/linearity trade-off. While the second one uses this principle to converts a 77 GHz RF signal by using a 26 GHz LO frequency thus simplifying the LO distribution chain of the receiver. The background of this study is introduced in the chapter 1 presenting the design trade-off related to the 77 GHz radar receiver and provides a review of the existing solutions. The following chapter describes the sampling mixer principle and the implementation of a 77 GHz sampling mixer in 28-nm FDSOI CMOS technology. Then, a sub- sampling mixer topology allowing to convert an RF signal around 77 GHz using a 26 GHz LO frequency is detailed in the chapter 3. The chapter 4 draws the conclusion of this study by showing the implementation of the two proposed sampling-based mixers with a low noise amplifier in 77 GHz front ends. These receiver architectures are compared with the state of the art highlighting the strengths and weaknesses of the proposed solutions. The results of this study demonstrates that using sampling for down conversion can be convenient to address millimeter-wave frequency applications

Packages for Terahertz Electronics

In the last couple of decades, solid-state device technologies, particularly electronic semiconductor devices, have been greatly advanced and investigated for possible adoption in various terahertz (THz) applications, such as imaging, security, and wireless communications. In tandem with these investigations, researchers have been exploring ways to package those THz electronic devices and integrated circuits for practical use. Packages are fundamentally expected to provide a physical housing for devices and integrated circuits (ICs) and reliable signal interconnections from the inside to the outside or vice versa. However, as frequency increases, we face several challenges associated with signal loss, dimensions, and fabrication. This paper provides a broad overview of recent progress in interconnections and packaging technologies dealing with these issues for THz electronics. In particular, emerging concepts based on commercial ceramic technologies, micromachining, and 3-D printing technologies for compact and lightweight packaging in practical applications are highlighted, along with metallic split blocks with rectangular waveguides, which are still considered the most valid and reliable approach.119Ysciescopu

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

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

Integrated Circuit and Antenna Technology for Millimeter-wave Phased Array Radio Front-end

Ever growing demands for higher data rate and bandwidth are pushing extremely high data rate wireless applications to millimeter-wave band (30-300GHz), where sufficient bandwidth is available and high data rate wireless can be achieved without using complex modulation schemes. In addition to the communication applications, millimeter-wave band has enabled novel short range and long range radar sensors for automotive as well as high resolution imaging systems for medical and security. Small size, high gain antennas, unlicensed and worldwide availability of released bands for communication and a number of other applications are other advantages of the millimeter-wave band. The major obstacle for the wide deployment of commercial wireless and radar systems in this frequency range is the high cost and bulky nature of existing GaAs- and InP-based solutions. In recent years, with the rapid scaling and development of the silicon-based integrated circuit technologies such as CMOS and SiGe, low cost technologies have shown acceptable millimeter-wave performance, which can enable highly integrated millimeter-wave radio devices and reduce the cost significantly. Furthermore, at this range of frequencies, on-chip antenna becomes feasible and can be considered as an attractive solution that can further reduce the cost and complexity of the radio package. The propagation channel challenges for the realization of low cost and reliable silicon-based communication devices at millimeter-wave band are severe path loss as well as shadowing loss of human body. Silicon technology challenges are low-Q passive components, low breakdown voltage of active devices, and low efficiency of on-chip antennas. The main objective of this thesis is to investigate and to develop antenna and front-end for cost-effective silicon based millimeter-wave phased array radio architectures that can address above challenges for short range, high data rate wireless communication as well as radar applications. Although the proposed concepts and the results obtained in this research are general, as an important example, the application focus in this research is placed on the radio aspects of emerging 60 GHz communication system. For this particular but extremely important case, various aspects of the technology including standard, architecture, antenna options and indoor propagation channel at presence of a human body are studied. On-chip dielectric resonator antenna as a radiation efficiency improvement technique for an on-chip antenna on low resistivity silicon is presented, developed and proved by measurement. Radiation efficiency of about 50% was measured which is a significant improvement in the radiation efficiency of on-chip antennas. Also as a further step, integration of the proposed high efficiency antenna with an amplifier in transmit and receive configurations at 30 GHz is successfully demonstrated. For the implementation of a low cost millimeter-wave array antenna, miniaturized, and efficient antenna structures in a new integrated passive device technology using high resistivity silicon are designed and developed. Front-end circuit blocks such as variable gain LNA, continuous passive and active phase shifters are investigated, designed and developed for a 60GHz phased array radio in CMOS technology. Finally, two-element CMOS phased array front-ends based on passive and active phase shifting architectures are proposed, developed and compared

Active and Reconfigurable Millimetre-Wave Antennas and Systems

PhDThe millimetre-wave (mm-wave) spectrum offers considerable advantages in terms of antenna form factor and spectrum availability. However, use of this region often requires reconfigurable antennas and systems. Initially, a review of the various applications which are taking hold in the lower regions of the mm-wave spectrum (30 to 100 GHz) is undertaken. Specifically, reconfigurable reflectarray technologies are selected for further research, and critical analysis of the reconfiguration techniques for including these in antennas is considered. Silicon as an optically activated semiconductor is chosen as the reconfiguration mechanism due to its low cost and the scope for improvement in this area. A new form of illumination is used, replacing traditional infra-red (IR) lasers with high power IR-LEDs enclosed in a cavity, increasing the efficiency of the silicon illumination. However, to make use of this novel illumination source, and subsequently integrate it into an antenna, the silicon response has to be characterised within Ka-band. This is done through measurements in a waveguide-based characterisation test cell, from which the complex electromagnetic properties of silicon under IR-LED illumination are retrieved with the aid of full-wave simulations. Using the measured conductivity properties of the illuminated silicon, reflectarrays with non-uniform amplitude distributions can be designed. Through variation of illumination intensities of IR-LEDs throughout the array, it is shown through measurements and full-wave simulations that unit cell reflections can be modified while phases are kept relatively constant. This theoretically allows switching between, for example a low side-lobe pattern binomial array, or a narrow beamwidth pattern Chebyshev array. To implement this, a novel multilayer unit-cell is designed, integrating the IR-LED. This is then used in a full reflectarray design which is measured. The key contributions of this work include the novel illumination mechanism and its integration into a reflectarray antenna, and the use of reconfigurable photoconductive materials to provide a mechanism for beam shaping and pattern synthesis at Ka-band.EPSRC DTC under grant number 135614

Center for Space Microelectronics Technology. 1993 Technical Report

The 1993 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 170 publications, 193 presentations, and 84 New Technology Reports and patents. The 1993 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 170 publications, 193 presentations, and 84 New Technology Reports and patents