Browsing by Issue Date, starting with "2024-11-07"
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- Automotive 4D Radar Imaging with Field of ViewPublication . Jesus, Samuel Viegas Reigota de; Caldeirinha, Rafael Ferreira da Silva; Reis, João Ricardo VitorinoRadio Detection And Ranging (Radar) technology has been around for many decades. Initially developed for military purposes, radar technology has now grown into a larger set of applications. It is used in aviation, to detect other aircrafts and give accurate altitude readings, in marine navigation, to prevent collision with other ships and monitor ship movements in busy waters, in weather forecast, to monitor precipitation and wind, in factories, to enable manufacturing robots to perceive their environment and navigate/position themselves according to it, and even in health care, to monitor breathing and blood pressure, to name a few. In recent years, improvements in integrated circuitry and Radio Frequency (RF) electronics have made radar-on-chip possible, significantly reducing production costs and therefore enabling a wider adoption of radar technology, now commonly used in many civil applications. In the automotive industry for instance, Millimeter Wave (mmWave) radar sensors are being implemented in everyday vehicles for purposes such as Collision Warning System (CWS), Blind Spot Detection (BSD), Autonomous Cruise Control (ACC), Parking Assistance Systems (PAS) and many more, thus being integrated in systems such as Advanced Driver Assistance Systems (ADAS) and Autonomous Driving Systems (ADS). These systems comprise a suite of electronic automotive technologies designed to assist drivers in various driving scenarios, enhance safety, and improve the overall driving experience by providing real-time data through a combination of software algorithms and sensors, including cameras, ultrasonic sensors, Light Detection And Ranging (Lidar) and radar. Using real-time data from each component, ADAS and ADS can perceive the environment, plan a response, and control the vehicle’s mechanical systems to execute the intended action. As the market pushes for higher levels of vehicle autonomy, both ADAS and ADS are becoming increasingly more complex and sophisticated, requiring improvements in radar technology to meet the evolving demands of these advanced systems. Therefore, this dissertation presents the work on the development of a 4 Dimensions (4D) Multiple-Input-Multiple-Output (MIMO) automotive imaging radar with a 360◦ Field-of- View (FoV). After a brief description of the proposed architecture, using three mmWave 4D imaging radar sensors (AWR1843BOOST) by Texas Instruments (TI), disposed in a equilateral triangular prism shape, this dissertation presents the first results on the implementation of a real-time and high resolution radar sensor with a 360◦ FoV. To conclude the performance evaluation of the presented 360◦ radar, experimental results obtained in a controlled environment, i.e. inside an anechoic chamber, are presented to validate the proposed concept. A mmWave Compact Antenna Test Range (CATR) anechoic chamber was also designed and built in order to properly calibrate the radar. Successful target detection is achieved by multi-point point-cloud. The proposed radar architecture may be seen as an opportunity to augment and improve ADAS and ADS.
- ADDITIVE MANUFACTURING FOR ANTENNA TECHNOLOGIESPublication . Carvalho, Saúl dos Santos; Caldeirinha, Rafael Ferreira da Silva; Reis, João Ricardo VitorinoThis dissertation explores the use of Additive Manufacturing (AM) technology, commonly known as Three-dimensional (3D) printing, for fabricating antennas, focusing on both static 3D and dynamic Four-dimensional (4D) printing techniques. It evaluates the cost-effectiveness and performance of these antennas compared to the ones fabricated using traditional methods (e.g. commercially available antennas). The study begins with the characterisation of dielectric properties of 3D printed materials through various extraction methods, which is crucial for accurate simulation and performance prediction. With this research several antennas were 3D printed and analysed, including pyramidal horn antennas, which were fully dielectric, with metallised polymers, with metal composites, and fully metallic, operating at K-Band. Additive manufacturing techniques, such as Laser Powder Bed Fusion (LPBF), were employed, with findings indicating that the resultant full metal horn antennas offered the best performance in terms of gain, impedance matching, and bandwidth. Additionally, the study examines 3D printed C-Band microstrip rectangular patch antennas. Results show that while 3D printed microstrip patch antennas can achieve reasonable efficiency and gain, they still lag behind traditional laminate-based antennas. A novel aspect of this research is the design of an X-Band pneumatic-deployable 4D petal horn antenna, which demonstrates potential for real-time adaptability through computational fluid dynamics and electromagnetic simulations. The dissertation concludes that 3D printing technology offers significant advantages for antenna fabrication, particularly in rapid prototyping and customisation. The emergence of 4D printing presents new possibilities for dynamic, adaptable antennas, though further research is needed to address material and fabrication challenges to fully harness its potential.