A decorrelated closely spaced array of four slot antennas backed with SIW cavities for MIMO communications

An array of four slot antennas backed with substrate integrated waveguide (SIW) cavities is presented for application to multiple input multiple output (MIMO) systems. Two 0.18 ¿ spaced antennas are decorrelated by the use of a rat race hybrid. An investigation based on simulations and measurements has been carried out. The impedance matching and the radiation characteristics of these structures were studied using the finite difference time domain (FDTD) technique. The array performance is judged by considering the correlation coefficients between the elements and the MIMO channel capacity.