Direction Finding in the Presence of Mutual Coupling

Abstract

The area of sensor array processing has attracted considerable interest in the signal processing community. The focus of this work has been on high resolution Direction Of Arrival (DOA) estimation algorithms that detect and locate aircrafts using radar systems. These algorithms exploit the fact that an electromagnetic wave that is received by an arrayofantenna elements reaches each element at di erent time instants. In practical antennas the elements of the array a ect each other through mutual coupling and this reduces the direction nding ability. The e ects of mutual coupling on direction nding are examined in this thesis. To be able to analyze the e ects of mutual coupling, the coupling needs to be calculated. Here, the coupling in a Uniform Linear Array (ULA) of thin and nite dipoles is calculated using basic electromagnetic concepts. The e ects of coupling on the estimation of the DOA is studied by calculating a lower bound on the variance of the DOA estimates, the Cramer-Rao