Optimising radio coverage for wireless media servers

A three element patch antenna array is designed for a 2×3 802.11n wireless home media server application for highdefinition video streaming at 2.4GHz. An efficiency comparison shows that the use of the RT/Duroid substrate results in a 3dB improvement in performance over the cheaper FR4 substrate. The RT/Duroid patches are characterised in terms of input responses, full (3D) radiation patterns and directivities, including mounting on the terminal and local environment. The performance of the MIMO system is evaluated in an office environment in terms of received power, data throughput, datagram error rate, coverage area, and delay jitter. Results are compared with commercial omnidirectional antennas. Although high performance is possible (data rate at least 40Mbps), it depends heavily on the orientation of the box due to the directional radiation of the patches. An antenna selection scheme may therefore prove beneficial in future designs.