A wideband circular array for frequency and 2D angle estimation

This paper presents a novel method for joint frequency and 2D angle estimation of incoming signals upon a circular array over a very wide frequency band (2-18 GHz). A temporal domain ESPRIT frequency estimation algorithm was extended for azimuth and elevation angles estimation. These direction estimation results are automatically paired with frequency. The algorithm provides non-ambiguous, high resolution and accuracy in both frequency and direction of arrival estimation over the frequency range. The DOA estimation resolution was analyzed for two signals with different frequency. The estimation accuracy vs. signal to noise ratio (SNR) and array element number were studied. The frequency estimation accuracy was compared with the standard FFT method. The DOA estimation accuracy and resolution were compared with the original MUltiple SIgnal Classification (MUSIC) DOA estimation results. The proposed technique can be used for wireless communication applications and wireless sensor networks and it can also be used for RF emitter detection and tracking. The system is consistent with the Air Force's layered sensing architecture concept.