Evaluating the effect of antenna tilt and rotation on antenna performance in an indoor environment

In this paper the relative performances of antenna elements are assessed by combining the measured full (3D) far-field radiation patterns of each with measured angle of arrival data for a laboratory/office space. Three element types (Cavity-backed Slot, Printed Inverted-F and Dielectric Resonator) at two positions on a small mobile terminal are considered, and the terminal is tilted and rotated in order to determine the variation in performance that is obtained for three transmitter locations. Results are presented as cumulative distribution functions of directivity relative to a benchmark Hertzian dipole for operation at 5.2GHz. A variation in signal strength of greater than 30dB was observed due to both the directivity of the elements and their polarisation alignment with the vertical transmitting source.