A Robust Sparse Fractal Array

The term fractal refers to the fractional dimensions that have recursive nature and exhibit better array factor properties. In this article, we present a new class of sparse arrays where the recursive nature of a fractals is used in designing an antenna array called a sparse fractal array by combining sparsity properties of the various sparse array and the recursive nature of the fractal array. The most important property of the proposed array is the hole-free difference coarray which makes it a good choice for DOA estimation. Upon carrying out the robustness analysis of the proposed geometry in sensor failure environment it is found that the proposed array is robust enough as compared to already existing sparse arrays which shows highest fragility value. Direction of arrival estimation of the uncorrelated sources using the proposed geometry showed the RMSE(root mean square error) value of the order of 10(-3) which proves it to be a good choice for the application of DOA estimation algorithms like MUSIC, ESPIRIT etc.