Enhancement of Direction-of-Arrival Estimation Accuracy with Using Antenna Arrays Composed of Diverse Elements

An antenna array composed of diverse elements that can improve direction-of-arrival (DoA) estimation accuracy is presented in this paper. As many surveillance and radio-frequency positioning systems relay on measuring DoAs, improving the DoA accuracy is of great importance. However, due to the limited array dimension, the DoA accuracy of the arrays composed of identical elements is fundamentally difficult to improve. Besides, given the limited number of elements, arbitrarily increasing the array dimension can cause ambiguity. To alleviate these issues, we employ antennas with diverse shapes of radiation patterns to improve the DoA estimation accuracy. We compared the DoA estimation accuracy of a uniform linear array of three rectangular patch antennas and that of the same array of two rectangular patch antennas and one low-profile antenna with a monopole-like radiation pattern. Theoretical and Monte Carlo simulation results demonstrate that the DoA estimation error of the array composed of diverse antennas can reduce by up to 30% over a wide field of view.