Binomial array as a multistate phase diversity antenna

If two in-phase plane waves arrive at an antenna from different directions, the resulting signal is not necessarily the coherent sum of the two incomi ng signals, This is due to the fact that the antenna radiation pattern is a ctually a complex quantity containing amplitude and phase properties. Thus, it can be stated that antenna phase characteristics may vary as a function of direction, In free space, the antenna phase pattern does not have any r ole in radio communications in contrast to mobile communications in an urba n microcell where the radio channel is very complicated due to multipath pr opagation. Array antennas offer possibilities to control its phase properti es in transmission and reception, which offer a simple technique to improve the combination of received multipath signal components, Binomial arrays a re one possibility to implement similar directive beams which, however, hav e different phase patterns compared to each other. A set of these beams cou ld be used in a discretely optimizing receiver system much in the same way as other diversity techniques are used. A four-element array and results fr om a microcell radio channel environment simulation are presented as a demo nstration of this technique.