Near-Field Monopulse DoA Estimation for Angle-Sensitive Proximity WiFi Readers

We study the effect of close-proximity in the estimation of the Direction-of-Arrival (DoA) using a monopulse antenna array system, with application to angle-sensitive proximity WiFi readers. It is shown that in this scenario, it is necessary to consider near-field radiative effects to make an accurate angular estimation at short distances between the mobile terminal and the DoA proximity sensor. As a result, we define a range-dependent angular monopulse function, which provides a better DoA estimation in a Field of View of 60° and for distances ranging from 3 m to 50 cm.