An Approach for Designing a Two-Element Antenna Array for Estimating the Spatial Coordinates of Radio Signals with Increased Accuracy

In the paper a simple and intuitive method for optimal placement of directional antenna elements for digital spatial signal processing with high accuracy is declared. The digital antenna arrays estimate the spatial coordinates with subsequent beamforming. However, as it is well known, the quality of the spatial spectrum analysis is mainly based on several factors such as the mutual arrangement of antenna elements, their number and shape of the elements' radiation pattern. The paper uses the early obtained expression for calculating the Cramer-Rao lower bound (CRLB) in order to reduce the number of antenna elements without degrading the accuracy of the direction-of-arrival (DOA) estimation. For example, the approach is examined for developing a two-element array. In the obtained array the antennas are designed to have a flat-top radiation pattern. It is shown that the accuracy of the method MUSIC via the obtained antenna array is higher in comparison with the three-element circular array.