Effect of mutual coupling on the performance of Direction-of-arrival estimation of compact array

With the recent advancement in microwave hardware, there has been significant focus on developing compact antenna arrays with element separation less than half wavelength. Direction-of-arrival (DOA) estimation is an important application for antenna arrays but yet not much work has been done on DOA estimation using compact arrays. In particular, as the element separation becomes smaller, the undesirable mutual coupling effect between antenna elements becomes much stronger which can significantly degrade the accuracy of DOA estimation.In this paper, we would like to investigate how this RMIM method performs for compact arrays with different omni-directional antenna elements. In particular, dipoles, monopoles and normal-mode helical antennas (NMHAs) are considered. DOA estimation using the Matrix Pencil Method (MPM) will be used as a platform to investigate how the RMIM and MPM perform in mutual coupling compensation for DOA estimation.