2-D DOA Estimation And The Study Of Mutual Coupling Compensation In The Microstrip Array

The beamforming algorithm and antenna array are two important parts of smart antenna systems. The correct estimation of incident signals' direction of arrivals (DOAs) is the premise of DOA-based beamforming algorithms. Microstrip antenna arrays can meet smart antenna's demands of miniaturization and low cost and will be used widely in modern communication systems. Practically, the DOA estimation is two- dimensional (2-D) and is affected by mutual coupling, which must be compensated for. First, this paper compares the performance of the signal space matrix (SSM) method with that of the 2-D unitary estimation of signal parameters via rotational invariance techniques (Unitary ESPRIT) method. To resove coherent sources, spatial smoothing approach is described. Second, we compute the self-impedance through cavity modal theory and mutual impendance based on reaction theory respectively. Then the generalized impedance matrix that reflects the effect of mutual coupling is formed. At last, the effect of mutual coupling on 2-D DOA estimation algorithms is investigated and two efficient methods of mutual coupling compensation are proposed.