Redovisade

Impedansanpassning av mobila MIMO-terminaler

David Olsson (E05)

Sammanfattning

Multiple-Input Multiple-Output (MIMO) is a promising new technique which makes it possible to increase the capacity of the wireless channel without increasing the required bandwidth. However, in order to benefit from significantly increased capacity, the MIMO system has to use spatial multiplexing which requires decorrelated antenna elements, and a scattering environment. A MIMO system also enables beamforming and diversity. In this master thesis, the performance of simulated and real antennas with two antenna elements each will be studied. The performance will be enhanced, both by changing the physical proportions of the antennas, and by implementing matching networks. To optimize these matching networks, an optimization software called Multiport Antenna Evaluator (MPA) will be introduced. MPA will first optimize matching networks on simulated antennas, and then on real antennas by importing farfield data from the anechoic chamber, and port responses from a network analyzer. It was shown that MPA is a useful tool when optimizing matching networks consider high total radiated efficiency and low correlation coefficient. However, the optimizations of the real antennas were limited to high efficiency due to unclear results.

Handledare: Anders Sunesson (Perlos) och Anders Karlsson (EIT)

Examinator: Anders Karlsson (EIT)