A Dual-Polarized Tapered Slot Antenna for UAV-Based Collection of Locally Coherent Field Data

Commonly employed near-field far-field transfor-mations (NFFFTs) require coherent (complex) measurement data. In contrast, phaseless NFFFTs work with magnitude-only measurements. The transformation success of phaseless data can be considerably improved by adding localized phase information in form of phase differences among neighbouring measurement samples, which can, e.g., be acquired by a cluster of coherent antenna receivers. Such an approach is especially suitable for near-field measurements based on unmanned-aerial-vehicles (UAVs). A probe element for the aforementioned application, which is operating between 1.5 to 4.5 GHz, is designed and realized in the form of a tapered slot antenna. The antenna is implemented as a printed circuit board version and also as a better performing machine-milled all-aluminium version. The resulting probe element is dual-polarized, light in weight, has a low aerodynamic profile and good back-radiation suppression (for UAV-mounting).