A 24-GHz Radar with 3d-Printed and Metallized Lightweight Antennas for UAV Applications

A 24-GHz frequency-modulated continuous-wave (FMCW) radar system and its possible use in airborne vehicles is presented in this paper. The focus of this paper is set on the ultralight antennas and their integration into radar systems for unmanned aerial vehicle (UAV) applications. For this purpose a radiator arrangement was designed and then 3d-printed twice out of plastics with various methods. Different metallization processes were used to establish conductivity afterwards. Particularly, one antenna was plated with a conventional method and one with a new metallization technique, which makes it feasible to cover a non conducting part with silver within seconds. The weight of the antenna is 7-8 times less, than compared to full metal antennas. Subsequently, both antennas were measured, characterized and compared to each other in terms of reflection loss and beam pattern. It will be shown that the antenna metallized by the new technology can achieve 2-3 dB better results in return loss than the conventionally plated one in the 24-GHz ISM band. Also it will be shown that both prototypes are similar regarding their gain. Moreover, the antennas were mounted onto a radar, located on the UAV and then flight tests up to 120 meters have been performed. These results were recorded, processed and evaluated finally.