Three orthogonal polarized antenna

Abstract

The demand for wireless communication systems has continued to grow steadily and a number oftechnological advances have been made during this growth. To increase system capacity for wirelesssystems by means of uncorrelated propagation paths, a MIMO (Multiple Input Multiple Output) systemhas been considered a better technology for improving the capacity. For a MIMO system to functionefficiently – uncorrelated or at least essentially uncorrelated - transmitted signals are required whichmeans in this context that the polarizations are essentially orthogonal to each other.In this experiment we designed a triple orthogonal polarized antenna with the radiation patterns equalto a dipole antenna for testing purposes. With three orthogonal antennas it should be easy to switchpolarization depending on the signals you want to be measured without having to move the structurephysically.Various possibilities have been examined such as patch antennas and wire antennas required toradiate 360 degrees in one plane. The main challenge was to find a structure that would allow thecabling to be connected to the antenna without interfering with any of the three orthogonal dipolepatterns.Another requirement was to have the same phase center for all three antennas so that measurementsfor all three polarizations can be made without moving the antenna or phase corrections