In this paper, two novel vector sensors using a reduced number of radiating elements are proposed to estimate the directions of arrival of incoming electromagnetic signals in the 3D space, azimuth and elevation angles. The first one uses co-located radiating elements while the other one is based on distributed antenna elements. These two sensors combine only two half-loops and one linear monopole placed on a metallic plate in view of embedded applications. Full wave electromagnetic simulations are performed to take into account the electromagnetic coupling effects between the antenna elements. The directions of arrival estimation accuracy of electromagnetic signals incoming in arbitrary directions in the full 3D space are computed from the MUSIC algorithm. For experimental validation purpose, a prototype is manufactured and the directions of arrival measurements are performed. Then a novel vector sensor design with a reduced number of antenna elements is presented. The antenna elements are spatially distributed. An analysis is carried out to determine the largest distance between the antenna elements without causing ambiguous estimations in the 3D space. The estimation accuracy of the resulting sensor is reported. Finally the performances of these two vector sensors are compared.