Performance Evaluation of Root Based Direction Finding Algorithms Using Hardware Emulation of the Antenna Array

To validate the theoretically predicted performance of root based direction finding (DF) algorithms an experimental test bed was assembled covering the 18501910 MHz band. A fourelement antenna array with uniform interelement spacing was emulated using variable phase shifters creating what is essentially a decoupled array environment. The array outputs were down converted using standard analogue circuits and fed to a fourchannel receiver providing four separate digitized data channels. The data were processed with the Modified Root Pisarenko (MRP) algorithm. The results show that using an equivalent physical array aperture of only 1.5 wavelength the directions of arrival (DOA) in a decoupled array environment can be estimated with errors smaller than 0.0