Background Large-aperture antennas are widely employed in radar, satellite communications, and deep-space exploration. Accurate measurement of their gain and radiation patterns requires far-field conditions; for high-frequency antennas, the far-field distance can reach several kilometers, posing significant challenges for conventional measurement methods.
Purpose To address the high cost, poor flexibility, and site constraints of traditional far-field measurement techniques for large-aperture antennas, this paper proposes and develops an automated antenna parameter measurement system based on a multirotor unmanned aerial vehicle (UAV) platform.
Methods The system is based on the Friis transmission formula. A UAV equipped with high-precision measurement payloads dynamically samples the antenna radiation field at the required distance. A “wide-beam antenna + high-torque three-axis gimbal” technique is employed to achieve continuous and stable measurement under flight conditions, while a measurement chain integrating frequency selection, power-level adjustment, and a high-precision power meter is designed to tackle the combined challenges of large dynamic range and high measurement accuracy. Furthermore, the system integrates automated flight path planning, centimeter-level real-time kinematic (RTK) positioning, and real-time data processing, and supports two measurement modes: “rotating the antenna under test” and “orbiting flight around the antenna.”
Results Field tests demonstrate that the system achieves a gain measurement error of approximately 0.3 dB and a dynamic range exceeding 80 dB.
Conclusions The proposed system enables efficient, accurate, and mobile measurement of large-aperture antenna gain and radiation patterns, offering an advanced and reliable solution for antenna field testing.
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