Joint DOA and Polarization Estimation With Crossed-Dipole and Tripole Sensor Arrays

Electromagnetic vector sensor arrays can track both the polarization and direction of arrival (DOA) of the impinging signals. For linear crossed-dipole arrays, as shown by our analysis, due to inherent limitation of the structure, it can only track one DOA parameter and two polarization parameters. For full 4-D (two DOA, and two polarization parameters) estimation, we could extend the linear crossed-dipole array to the planar case. In this article, instead of extending the array geometry, we replace the crossed-dipoles by tripoles and construct a linear tripole array. Detailed proof shows that such a structure can estimate the 2-D DOA and 2-D polarization information effectively in general. A brief comparison between the planar crossed-dipole array and the linear tripole array is performed at last, showing that although the planar structure has a better performance, it is achieved at the cost of increased physical size.