An eigen-analysis of a compact L-quad antenna array for direction finding

The aim of this paper is to analyze the coupling between elements in an array designed for direction of arrival (DoA) estimation for different arrangements, using an eigen-analysis approach. When designing an array for applications such as DoA estimation, it is important not only to focus on the antenna performance but also to analyze parameters such as the Cramér-Rao Lower Bound (CRLB), which will be reviewed in this work for direction finding. The connection between the CRLB and the coupling between elements in an antenna array will be drawn using the eigenefficiencies computed. The paper focuses on compact antenna arrays, and their performance for several inter-elements spacing will be analyzed in order to evaluate the array configuration that renders both maximum direction finding capability and maximum radiation efficiency.