Accuracy of harmonic analysis techniques for direction of arrival estimation using time modulated arrays

This paper presents a comparison between two direction of arrival (DoA) estimation methods using time modulated linear arrays (TMLAs). The first method uses a two element array and numerically derives the signal DoA by using the ratio of the two harmonics created by array. The second method makes use of a greater number of elements and known steering angles of the array sidebands. Results of a numerical simulation are presented which detail the accuracy in direction finding when using the two techniques while the array is subject to environmental conditions such as noise and coherent signal interference. It is shown that whilst the second method requires a greater number of elements, it has greater immunity to noise and multipaths.