Wide Beamwidth Circularly Polarized Antenna Arrays for Bluetooth Direction Finding
Virtanen, Paju (2024)
Virtanen, Paju
2024
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2024-04-30
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202404053308
https://urn.fi/URN:NBN:fi:tuni-202404053308
Tiivistelmä
Location of different objects inside buildings, where the Global Positioning System (GPS) does not work, can be achieved with Indoor Positioning Systems (IPS) based on Bluetooth Direction Finding. Different objects for example in warehouses, hospitals, and military environments attached with a Bluetooth tag can be found with several locators detecting the Angle of Arrival of the signal of the tag. Angle of Arrival (AoA) is a direction finding algorithm, as well as Angle of Departure (AoD) and Multiple Signal Classification (MUSIC). In this thesis, above mentioned direction finding algorithms are applied and the direction finding performance of CoreHW 2 x 2 and 4 x 4 PCB antenna array for Bluetooth® Low Energy 5.1 AoX direction finding systems are simulated and measured. Their Axial Ratio (AR) and positioning accuracy are studied. It was found that these patch antenna arrays achieve a wide beamwidth while holding circular polarization (CP) and have under 0.2 meter positioning accuracy at best. With a wider beamwidth and circularly polarized antenna array, it is possible to detect incident signals at a wide angle. Great positioning accuracy in different modes enables IPS to work in different interiors.