Direction of arrival estimation using ESPRIT with mutual coupling compensation

The performance of ESPRIT in direction of arrival estimation at linear array monopole antennas operating at 2.4 GHz is investigated. The mutual coupling that occurs between elements of the array is compensated for by using two techniques. The first technique is the open-circuit voltage method and the second method involves redefining the mutual impedance so that it can characterise the mutual coupling effect. The calculation of the redefined mutual impedance is based on an estimate at the current distribution. The redefined mutual impedance is more accurate than the conventional mutual impedance in quantifying the mutual coupling. Simulation results show that the second compensation approach gives a much more accurate estimation of the directions of arrival than the open circuit voltage compensation approach when two signals are placed close together.