A Hybrid Diversity Antenna System

To increase link gains and enhance performance in wireless systems, antenna diversity has long been used. Such diversity provides a means not only to overcome the effects of signal multipath and fading in realistic RF channels or propagation environments but also to increase channel capacity. In this paper, we propose a design that uses hybrid combining of two types of antenna diversity, spatial and polarization, for a consistently better received RF signal. The design is adaptive in that it periodically tests signal strength on a number of channels, and selects those which provide the better signals at that time. A four-choose-two system was developed and prototyped. About 5 dB in power gain over the reference non-hybrid system was achieved. A significant reduction in signal power variance (about 2.3 dB) was also observed experimentally.