In this thesis, a novel System-on-Package (SoP) antenna concept has been developed for 24 GHz automotive radar applications. High-performance applications such as automotive radars require miniaturization, excellent performance and a high level of integration. The multi-layer Low-temperature co-fired ceramic (LTCC) SOP approach is an effective solution to meet these stringent needs as it offers not only great capability of integrating embedded functions, but also the real estate efficiency and cost-savings. The antenna concept utilizes a mixed LTCC tape system and combines for the first time a fractal antenna array and an integrated grooved Fresnel lens. The overall gain of the system is 15 dB which includes a 6 dB gain enhancement due to the integration of the lens. The bandwidth is 1.8 GHz which is 7.5% of the center frequency. The three types of dielectric Fresnel lenses (grooved, multi-dielectric and perforated) have been investigated as gain enhancement and beam shaping components for high performance LTCC SoP applications. A high dielectric constant material has been utilized to realize the lenses in the LTCC medium. All three lenses perform well with significant gain enhancement (>6 dB) and beam shaping despite their compact sizes (2.4 cm x 2.4 cm). The excellent performance makes all three lenses highly suitable for high performance SoP applications with the grooved lens being most suitable due to the relative ease of fabrication.

This thesis examines the use of two coupled loops as an alternative method of connection for high frequency signals between passive elements on microwave laminates and integrated circuits; replacing traditional interconnect methods such as wire bonds and solder bumps which require costly back end of line processing. The loops harness both electric and magnetic fields in order to create the interconnection, and can be placed around the perimeter of the IC; here they do not interfere with placement of the existing electronics on the chip, or occupy space which may be required for large components such as spiral inductors. A parametric model for these coupled loops was developed in this thesis. This model allows for rapid initial dimension choice when provided a variety of different parameters such as the IC process geometry, and loop stack geometry. Once initial dimensions are obtained from the model, full-wave simulation can be used to finalize the design and examine effects of process design rules such as metal density requirements. Following model development a prototype system, consisting of a two metallic loops (one located on a low-loss microwave laminate, the other on a 0.13 u m CMOS IC), was fabricated. These loops were then stacked in order to couple the signal from a planar antenna array (printed on the laminate) onto the IC. This antenna-to-chip system was simulated and measured to have center frequencies of 25 GHz and 23 GHz respectively, with a peak gain greater than 5 dBi at the beams broadside (8 dBi in simulation). These results agree quite well, with discrepancies arising primarily from the presence of adhesive between the loops. This adhesive wicked underneath the IC during assembly, which was not accounted for during simulation, but can easily be done so. The radiation pattern from the antenna was measured to have a HPBW of 16 degrees in the elevation plane and 100 degrees in the azimuth plane. These correspond nicely with simulated results and produce a suitable system for automotive radar application; where harsh environments present difficulties to current interconnects such as wire bonds. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-09-09 21:55:06.971

<p>Automotive Radars have introduced various functions on automobiles for driver’s safety and comfort, as part of the Intelligent Transportation System (ITS) including Adaptive Cruise Control (ACC), collision warning or avoidance, blind spot surveillance and parking assistance. Although such radar systems with 24 GHz carrier frequency are already in use but due to some regulatory issues, recently a permanent band has been allocated at 77-81 GHz, allowing for long-term development of the radar service. In fact, switchover to the new band is mandatory by 2014.</p><p>A frequency multiplier will be one of the key components for such a millimeter wave automotive radar system because there are limitations in direct implementation of low phase noise oscillators at high frequencies. A practical way to build a cost-effective and stable source at higher frequency is to use an active multiplier preceded by a high spectral purity VCO operating at a lower frequency. Recent improvements in the performance of SiGe technology allow the silicon microelectronics to advance into areas previously restricted to compound semiconductor devices and make it a strong competitor for automotive radar applications at 79 GHz.</p><p>This thesis presents the design of active frequency doubler circuits at 20 GHz in a commercially available SiGe BiCMOS technology and at 40GHz in SiGe bipolar technology (Infineon-B7h200 design). Buffer/amplifier circuits are included at output stages to drive 50 Ω load. The frequency doubler at 20 GHz is based on an emitter-coupled pair operating in class-B configuration at 1.8 V supply voltage. Pre-layout simulations show its conversion gain of 10 dB at -5 dBm input, fundamental suppression of 25dB and NF of 12dB. Input and output impedance matching networks are designed to match 50 Ω at both sides.</p><p>The millimeter wave frequency doubler is designed for 5 V supply voltage and has the Gilbert cell-based differential architecture where both RF and LO ports are tied together to act as a frequency doubler. Both pre-layout and post-layout simulation results are presented and compared together. The extracted circuit has a conversion gain of 8 dB at -8 dB input, fundamental suppression of 20 dB, NF of 12 dB and it consumes 42 mA current from supply. The layout occupies an area of 0.12 mm2 without pads and baluns at both input and output ports. The frequency multiplier circuits have been designed using Cadence Design Tool.</p>

Automotive Radars have introduced various functions on automobiles for driver’s safety and comfort, as part of the Intelligent Transportation System (ITS) including Adaptive Cruise Control (ACC), collision warning or avoidance, blind spot surveillance and parking assistance. Although such radar systems with 24 GHz carrier frequency are already in use but due to some regulatory issues, recently a permanent band has been allocated at 77-81 GHz, allowing for long-term development of the radar service. In fact, switchover to the new band is mandatory by 2014. A frequency multiplier will be one of the key components for such a millimeter wave automotive radar system because there are limitations in direct implementation of low phase noise oscillators at high frequencies. A practical way to build a cost-effective and stable source at higher frequency is to use an active multiplier preceded by a high spectral purity VCO operating at a lower frequency. Recent improvements in the performance of SiGe technology allow the silicon microelectronics to advance into areas previously restricted to compound semiconductor devices and make it a strong competitor for automotive radar applications at 79 GHz. This thesis presents the design of active frequency doubler circuits at 20 GHz in a commercially available SiGe BiCMOS technology and at 40GHz in SiGe bipolar technology (Infineon-B7h200 design). Buffer/amplifier circuits are included at output stages to drive 50 Ω load. The frequency doubler at 20 GHz is based on an emitter-coupled pair operating in class-B configuration at 1.8 V supply voltage. Pre-layout simulations show its conversion gain of 10 dB at -5 dBm input, fundamental suppression of 25dB and NF of 12dB. Input and output impedance matching networks are designed to match 50 Ω at both sides. The millimeter wave frequency doubler is designed for 5 V supply voltage and has the Gilbert cell-based differential architecture where both RF and LO ports are tied together to act as a frequency doubler. Both pre-layout and post-layout simulation results are presented and compared together. The extracted circuit has a conversion gain of 8 dB at -8 dB input, fundamental suppression of 20 dB, NF of 12 dB and it consumes 42 mA current from supply. The layout occupies an area of 0.12 mm2 without pads and baluns at both input and output ports. The frequency multiplier circuits have been designed using Cadence Design Tool.

<p>Since their introduction by Mercedes Benz in the late 1990s, W-band radars operating at 76-77 GHz have found their way into more and more passenger cars. These automotive radars are typically used in adaptive cruise control, pre-collision sensing, and other driver assistance systems. While these systems are usually only about the size of two stacked cigarette packs, system size, and weight remains a concern for many automotive manufacturers.</p><p>In this dissertation, I discuss how artificially structured metamaterials can be used to improve lens-based automotive radar systems. Metamaterials allow the fabrication of smaller and lighter systems, while still meeting the frequency, high gain, and cost requirements of this application. In particular, I focus on the development of planar artificial dielectric lenses suitable for use in place of the injection-molded lenses now used in many automotive radar systems.</p><p>I begin by using analytic and numerical ray-tracing to compare the performance of planar metamaterial GRIN lenses to equivalent aspheric refractive lenses. I do this to determine whether metamaterials are best employed in GRIN or refractive automotive radar lenses. Through this study I find that planar GRIN lenses with the large refractive index ranges enabled by metamaterials have approximately optically equivalent performance to equivalent refractive lenses for fields of view approaching ±20°. I also find that the uniaxial nature of most planar metamaterials does not negatively impact planar GRIN lens performance.</p><p>I then turn my attention to implementing these planar GRIN lenses at W-band automotive radar frequencies. I begin by designing uniform sheets of W-band electrically-coupled LC resonator-based metamaterials. These metamaterial samples were fabricated by the Jokerst research group on glass and liquid crystal polymer (LCP) substrates and tested at Toyota Research Institute- North America (TRI-NA). When characterized at W-band frequencies, these metamaterials show material properties closely matching those predicted by full-wave simulations.</p><p>Due to the high losses associated with resonant metamaterials, I shift my focus to non-resonant metamaterials. I discuss the design, fabrication, and testing of non-resonant metamaterials for fabrication on multilayer LCP printed circuit boards (PCBs). I then use these non-resonant metamaterials in a W-band planar metamaterial GRIN lens. Radiation pattern measurements show that this lens functions as a strong collimating element.</p><p>Using similar lens design methods, I design a metamaterial GRIN lens from polytetrafluoroethylene-based (PTFE-based) non-resonant metamaterials. This GRIN lens is designed to match a target dielectric lens's radiation characteristics across a ±6° field of view. Measurements at automotive radar frequencies show that this lens has approximately the same radiation characteristics as the target lens across the desired field of view.</p><p>Finally, I describe the development of electrically reconfigurable metamaterials using thin-film silicon semiconductors. These silicon-based reconfigurable metamaterials were developed in close collaboration with several other researchers. My major contribution to the development of these reconfigurable metamaterials consisted of the initial metamaterial design. The Jokerst research group fabricated this initial design while TRI-NA characterized the fabricated metamaterial experimentally. Measurements showed approximately 8% variation in transmission under a 5 Volt DC bias. This variation in transmission closely matched the variation in transmission predicted by coupled electronic-electromagnetic simulation run by Yaroslav Urzhumov, one of other contributors to the development of the reconfigurable metamaterial.</p> / Dissertation

abstract: State-of-the-art automotive radars use multi-chip Frequency Modulated Continuous Wave (FMCW) radars to sense the environment around the car. FMCW radars are prone to interference as they operate over a narrow baseband bandwidth and use similar radio frequency (RF) chirps among them. Phase Modulated Continuous Wave radars (PMCW) are robust and insensitive to interference as they transmit signals over a wider bandwidth using spread spectrum technique. As more and more cars are equipped with FMCW radars illuminate the same environment, interference would soon become a serious issue. PMCW radars can be an effective solution to interference in the noisy FMCW radar environment. PMCW radars can be implemented in silicon as System-on-a-chip (SoC), suitable for Multiple-Input-Multiple-Output (MIMO) implementation and is highly programmable. PMCW radars do not require highly linear high frequency chirping oscillators thus reducing the size of the final solution. This thesis aims to present a behavior model for this promising Digitally modulated radar (DMR) transceiver in Simulink/Matlab. The goal of this work is to create a model for the electronic system level framework that simulates the entire system with non-idealities. This model includes a Top Down Design methodology to understand the requirements of the individual modules’ performance and thus derive the specifications for implementing the real chip. Back annotation of the actual electrical modules’ performance to the model closes the design process loop. Using Simulink’s toolboxes, a passband and equivalent baseband model of the system is built for the transceiver with non-idealities of the components built in along with signal processing routines in Matlab. This model provides a platform for system evaluation and simulation for various system scenarios and use-cases of sensing using the environment around a moving car. / Dissertation/Thesis / Masters Thesis Engineering 2019

Sensors, as a crucial part of autonomous driving, are primarily used for perceiving the environment. The recent deep learning development of different sensors has demonstrated the ability of machines recognizing and understanding their surroundings. Automotive radar, as a primary sensor for self-driving vehicles, is well-known for its robustness against variable lighting and weather conditions. Compared with camera-based deep learning development, Object detection using automotive radars has not been explored to its full extent. This can be attributed to the lack of public radar datasets. In this thesis, we collect a novel radar dataset that contains radar data in the form of Range-Azimuth-Doppler tensors along with the bounding boxes on the tensor for dynamic road users, category labels, and 2D bounding boxes on the Cartesian Bird-EyeView range map. To build the dataset, we propose an instance-wise auto-annotation algorithm. Furthermore, a novel Range-Azimuth-Doppler based multi-class object detection deep learning model is proposed. The algorithm is a one-stage anchor-based detector that generates both 3D bounding boxes and 2D bounding boxes on Range-AzimuthDoppler and Cartesian domains, respectively. Our proposed algorithm achieves 56.3% AP with IOU of 0.3 on 3D bounding box predictions, and 51.6% with IOU of 0.5 on 2D bounding box predictions. Our dataset and the code can be found at https://github.com/ZhangAoCanada/RADDet.git.

Precise and robust automotive localization is a must for autonomous vehicles. Radar is a cheap and robust sensor, and this project aimed to find a method to use automotive radar to localize globally. By using radar data to build occupancy grids based on other state-of-the-art radar localization methods, and applying image correlation techniques, a localization precision of below 20 cm could be achieved, delivering poses at frequency higher than 0.5 Hz along with a characterization of the uncertainty. By using an improved sensor model for the occupancy grid mapping, filtering the radar data, and using image correlation in the Fourier domain. The presented results are better than the state-of-the-art radar localization methods, both in terms of precision and frequency, however not in terms of heading estimation. The work provides a foundation for future investigations and improvements of radar as a sensor for localization. / Exakt och robust fordonslokalisering är ett måste för framtidens autonoma fordon. Radar är billig och robust sensor, och detta projekt utfördes i syfte att hitta en metod för att använda bilradar för att lokalisera globalt. Genom att använda radardata för att bygga occupancyg grids baserade på de senaste bästa radarlokaliseringsmetoder och tillämpa bildkorrelationstekniker, kunde en lokaliseringsprecision bättre än 20 cm uppnås, vilket ger positioner vid frekvens högre än 0,5 Hz tillsammans osäkerhetens karaktärisering. Genom att använda en förbättrad sensormodell för kartläggning av occupancy grids, filtrera radardata och använda bildkorrelation i Fourier- domänen. De presenterade resultaten är bättre än de senaste metoderna för radarlokalisering, både när det gäller precision och frekvens, men inte när det gäller riktning. Arbetet utgör en grund för framtida undersökningar av radar som en sensor för lokalisering.

No description available.

L’amélioration de la sécurité routière ainsi que le développement des systèmes de transports intelligents sont des enjeux d’avenir dans le secteur automobile avec un essor considérable du véhicule semi autonome et autonome. Les systèmes de sécurité active qui équipent de plus en plus les véhicules commercialisés utilisent des capteurs radar (longue et courte portée) fonctionnant dans les bandes 24 GHz ou 77 GHz. L’étude et la mise au point de tels capteurs peuvent être facilitées via l’utilisation d’une plate-forme de simulation générique permettant de simuler un système radar couplé à son environnement selon des scénarios types prédéfinis. Il est alors nécessaire de disposer d’une représentation fiable et réaliste de l’environnement et des objets présents.Cette thèse aborde la caractérisation et la modélisation du canal de propagation et plus largement de l’environnement radioélectrique en ondes millimétriques pour des applications radar, en termes de phénomènes de propagation (trajets multiples, réflexion, diffraction …) et de cibles électriquement larges. Une combinaison de méthodes asymptotiques a été mise en œuvre afin de permettre l'analyse de problèmes électriquement larges en bande W, tout en réduisant les exigences en temps de calcul et en capacité de mémoire. La précision du simulateur a été évaluée à l’aide d’une campagne de mesures de SER de cibles canoniques et complexes de petite taille (inférieure 6cm) dans une chambre anéchoïque. Le banc de mesure mis en œuvre a permis également de valider une procédure expérimentale de détermination de la signature radar. En effet, la procédure expérimentale a été généralisée à la mesure de la signature radar d’objets de taille réelle, dans un milieu « indoor ». Les mesures effectuées ont montré une bonne adéquation avec les résultats présentés dans la littérature. En outre, ces données expérimentales permettent d’extraire une description de la cible par des points brillants qui modélisent les phénomènes de diffusion et de réflexion spéculaire. La réponse à haute fréquence d’une cible peut être approchée par la somme de réponses de ses points brillants. On propose ainsi de simplifier les signatures mesurées pour maximiser l'efficacité de calcul. Comparé aux modèles géométriques détaillés d’une cible complexe, le modèle de points brillants conduit à une meilleure efficacité des simulations de propagation basées sur des rayons dans des scénarios routiers. Le modèle tient également compte de l’anisotropie des diffuseurs (dans le plan azimutal) en modélisant leurs amplitudes par des gaussiennes. / Improving road safety as well as the development of intelligent transport systems are issues of the future in the automotive sector with a considerable rise of the semi-autonomous and autonomous vehicle. The active safety systems that increasingly equip commercial vehicles use radar sensors (long and short range) operating in the 24 GHz or 77GHz bands. The study and development of such sensors can be facilitated through the use of a generic simulation platform to simulate a radar system coupled to its environment according to predefined standard scenarios. It is then necessary to have a reliable and realistic representation of the environment as well as targets. This thesis deals with the characterization and modelling of the propagation channel for radar applications, in terms of propagation phenomena (multipath, reflection, diffraction …) and electrically large targets. A combination of asymptotic methods was developed for the analysis of electrically large problems in W band, while reducing the requirements in CPU time and memory. The accuracy of the simulator was evaluated with radar cross section measurement of canonical and complex small targets (not exceeding 6 cm) in an anechoic chamber. The developed bench measurement also made it possible to validate an experimental procedure for determining the radar signature. Indeed, the experimental characterization was generalized to characterize various automotive related targets in an “indoor” environment. Measurement results matched well with the results presented in the literature. Moreover, the experimental data allows the extraction of a simple target description in terms of scattering points which model the diffusion and specular reflection phenomena. The high frequency response of a target can be approached by the sum of the responses of its scattering centres. It is thus proposed to simplify the measured signatures in order to increase the computation efficiency. Compared to detailed geometrical representation of a complex target, scattering centre model leads to better efficiency of ray-based propagation simulations of road scenarios. The model also takes into account the scattering centre anisotropy (in the azimuth plan) by modelling their amplitudes by Gaussian ones.