For antenna measurements, the device under test (DUT) is usually transported to an anechoic chamber equipped with a scanner system. To measure on-site, unmanned aerial vehicles (UAVs) are a flexible solution as they can precisely maneuver a probe antenna over a surface in the DUT’s near-field region. In this work, the designed multi-rotor UAV enables electromagnetically optimal placement of the probe antenna and effective gravity center re-balacing by payload position adjustment. The on-board software-defined radio (SDR) serves as a dual-channel receiver for the dual-polarized probe and as a signal source. For phase-coherent measurements, the source signal is transmitted to the DUT via an optical fiber tethering the UAV to the ground control station. Power supply cables allow unlimited flight times. A laser-based tracking system originating from virtual reality (VR) applications measures the probe position and orientation. The developed operator software guides the UAV along a trajectory and records the irregularly distributed near-field samples. An inverse equivalent sources solver (IESS) with full probe correction computes equivalent sources for antenna diagnostics and the DUT far field. The deployed components make the system very cost-effective. Still, verification measurements demonstrate its usability and the accuracy of the results for frequencies up to several GHz.

中文翻译：

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一种经济高效的系留无人机相干近场天线测量系统


对于天线测量，被测设备 (DUT) 通常被运输到配备扫描仪系统的消声室。对于现场测量，无人机 (UAV) 是一种灵活的解决方案，因为它们可以在 DUT 近场区域的表面上精确地操纵探头天线。在这项工作中，设计的多旋翼无人机能够实现探测天线的电磁优化放置，并通过有效负载位置调整来有效地重新平衡重心。板载软件定义无线电 (SDR) 充当双极化探头的双通道接收器和信号源。对于相位相干测量，源信号通过将无人机连接到地面控制站的光纤传输到 DUT。电源线允许无限的飞行时间。源于虚拟现实 (VR) 应用的基于激光的跟踪系统可测量探头位置和方向。开发的操作软件引导无人机沿轨迹飞行并记录不规则分布的近场样本。具有完整探头校正功能的逆等效源求解器 (IESS) 可计算天线诊断和 DUT 远场的等效源。所部署的组件使系统非常经济高效。尽管如此，验证测量仍证明了其可用性以及高达几 GHz 频率结果的准确性。