Antenna measurements of vehicle mounted antennas in the DAB frequency band using an integrated UAV system

In this thesis, it has been designed, constructed and tested an integrated measurement system for performing electric field strength measurements in the far-field, mounted on a drone, known as multicopters. The system uses a small portable spectrum analyzer with a single board computer that handles data from the flight controller on the drone and controls the measurements. The method used to solve the project is an experimental approach, a prototype was created to solve the problem. The system is tested and constructed for the Digital Audio Broadcast frequency band at (174-240) MHz, using a target frequency of 221.208 MHz. The antennas selected for the measurements were two common DAB antennas for vehicles, one mounted on the roof with a magnetic base and one mounted on the windshield at the driver side. The measurement results show that there is some inaccuracy due to a low position logging rate of the Global Navigation Satellite System receiver on the drone. The results are used in Matlab to represent the radiation patterns of the antennas in both the azimuth and elevation plane, but with the use of interpolation to define the most likely form of the radiation diagram. It is also possible to see from the results where the directivity of the antennas is pointing. The results show that the logging of the positions should be improved to create a better resolution of the radiation patterns. It should also be developed a program in Matlab that can display the radiation patterns in three-dimensional graphs, in this way creating a better picture of the coverage of the antennas. Also, to make the system more versatile, it should be tested for other types of antennas and with other frequencies, so it can be explored if the system is durable for all types of antenna measurements