Reduction of the sensor number in distributed vector-antennas for 3D direction finding

For 3D direction finding, one can use vector-sensor antennas. For such antennas, a linear system can been introduced to determine the field components at one point from the measured signals. The condition number of this system evaluates the sensitivity of the antenna to small perturbations. The previous method leads to antennas with a large number of elements. To reduce this number, a feeding network is added that is defined from a singular value decomposition. Numerical experiments are realized to test its performance.