Abstract
The Internet of Things (IoT) will require billions of interconnected devices that can communicate with each other and act based on their environment without human supervision. To ensure uninterrupted connectivity, omnidirectional antennas are typically preferred because they can cover a large area with their radiation. Recently, there has also been interest in quasi-isotropic antennas, which can radiate in all directions regardless of the transmitter-receiver orientation. However, this approach has inherent drawbacks. IoT devices at the edge of the network are energy-constrained, and a significant portion of power is wasted on non-essential radiation when these large coverage antennas are implemented. Additionally, continuous and uncontrolled electromagnetic (EM) radiation contributes to ambient EM pollution. When combined with the projected growth of IoT devices, this raises the chances of interference between devices, leading to potential information loss in dynamic scenarios. Thus, there is an urgent demand for adaptive antenna designs tailored for power-starved devices that possess environment-awareness capabilities, enabling efficient radiation reconfiguration while remaining suitable for dynamic large-scale deployment. This dissertation proposes 3D smart Antenna-in-Package (AiP) designs that are aware of their surroundings and can reconfigure their radiation based on orientation and the radiofrequency (RF) environment. Additive manufacturing techniques (3D and screen printing) have been explored for cost-effective manufacturing, crucial for deploying billions of IoT devices. The AiP concept itself is cost and space-effective as the antenna is integrated into the device's package, eliminating the need for a separate substrate. Smart reconfiguration is achieved by implementing independently activated microstrip patch antennas (MPA) on each face of the 3D AiP, while the electronics are embedded within the package. The MPAs' ground planes are cleverly used to form an EM-shielded core to isolate the antennas from the contained electronics. Three designs are presented: Firstly, a cubic MPA-based AiP offering focused boresight and quasi-isotropic radiation patterns. The focused mode increases received power, while the quasi-isotropic mode ensures low gain variation in the 3D sphere. Secondly, a dodecahedral circularly polarized (CP) AiP with volumetric phased array (VPA) behavior provides higher resolution directivity in gain and polarization, enhancing robustness against orientation misalignment in IoT systems. Lastly, a field-deployable sensor node (SN) integrates an optically transparent AiP with solar harvesting modules and multiple gas sensors for distributed air quality monitoring. These designs are tailored for power-constrained applications, offering enhanced performance, integration capabilities, and optimized IoT connectivity.
Brief Biography
Maria Bermudez Arboleda received a B.Sc. degree in physics engineering from the National University of Colombia, Medellin, Colombia, in 2017, and an M.Sc. degree in electrical and computer engineering from King Abdullah University of Science and Technology, Saudi Arabia, where she is currently pursuing the Ph.D. degree. Her research interests include re-configurable antenna systems, Antenna-in-Package, wireless sensing, IoT, and wearables.
