Design of a Novel Antenna Array for MIMO Applications

In spite of the good benefits of using MIMO technology with modern wireless systems, a major problem has arisen from using it with small wireless terminals. When antennas are placed with less than half wavelength apart then mutual coupling occurs. Researchers have found that mutual coupling can affect the performance achieved by multiple antennas which results in a large reduction in channel capacity. In this paper a practical hybrid circuit is designed for a 2times2 MIMO system to confirm a recent theory which states that a decorrelation network can be used with mutually coupled MIMO antennas to improve the performance. The hybrid circuit was tested with stacked patch antennas and performance was evaluated using cumulative distribution function curves on channel capacity at 5.2 GHz. Results show that some improvement was achieved with the hybrid and results can be further improved by some other manipulations.