Frequency-Scanned Focused Leaky-Wave Antennas for Direction-of-Arrival Detection in Proximity BLE Sensing Applications

Abstract

The synthesis of monopulse functions in the Fresnel region, using near-field focused leaky-wave antennas (LWA), is presented in this work. The focusing technique, combined with the frequency-scanning behavior of LWAs, allows for obtaining well-defined radiation patterns in the vicinity of the antenna, which properly overlap to obtain the scanning monopulse functions. This is not possible with conventional far-field focused antennas, in which the radiation pattern is very distorted in the near-field region. As a proof of concept, examples using the three advertising channels provided by the Bluetooth Low Energy (BLE) protocol are shown. These channels (#37, #38 and #39) are placed at 2.402, 2.426 and 2.48 GHz, respectively. The near-field monopulse synthesis is interesting for Direction-of-Arrival (DoA) detection in proximity sensing applications.