Multi-band base station antenna for diversity and MIMO-applications

In this paper an antenna element for the application in multi band base station antennas for mobile communication systems is presented. The antenna element covers the most important frequency bands in Europe and Asia (GSM 1800, UMTS at 2100 GHz and UMTS-Plus at 2600 MHz), respects important features regarding manufacturing, signal distribution and signal intermodulation. Since the antenna can be fed independently by two orthogonal feeds, polarization diversity can be realized within a single antenna element. This can be used for polarization diversity and in MIMO systems to adapt the antenna to the channel. The possible system enhancement due to the polarization diversity feature within a single antenna element will be derived.