Direction-of- Arrival Estimation with a 7-Element Regular-Hexagonal Shaped ESPAR Antenna Employing the ESPRIT Algorithm

摘要

The electronically steerable parasitic array radiator (ESPAR) antenna is a single-output array antenna. As the output signal of each element of the antenna cannot be observed, direct application of most of the algorithms designed for the conventional array antenna is impractical. In this paper a technique for Direction-of- Arrival (DoA) estimation for the ESPAR antenna based on the ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) algorithm combined with the reactance domain technique is proposed. ESPRIT is a well-known subspace-based approach for high-resolution signal parameters with applications to DoA estimation. Three configurations of lozenge-shaped subarray partition sets were, heuristically, found within the 7-element regular-hexagonal shaped ESPAR antenna. So, by exploiting the displacement invariance provided by these partition sets, DoA estimations can be performed with the ESPRIT algorithm. Simulations show that the performance of the algorithm is linked to the value of the angle of arrival. Because of the subarray division imposed on the ESPAR antenna by the ESPRIT algorithm, DoA estimations are restricted to half of the full azimuthal plane sector. Nevertheless, by employing the proposed method, up to three signals impinging simultaneously can be estimated. Moreover, good results can be obtained: for one signal impinging on the ESPAR antenna, simulations show that there is a probability of more than 80% of achieving DoA estimations within ±2° accuracy for an angle in the range of 50° to 130°.