RAPTAR: Radar Radiation Pattern Acquisition through Automated Collaborative Robotics

2025-07-22

AI Summary

Current on-chip antenna characterization is hindered by narrow angular coverage of probe stations, reliance on custom hardware, and manual alignment—limiting rapid, accurate testing in practical scenarios such as automotive and UAV applications. This paper introduces the first portable, fully automated robotic radiation pattern measurement framework. Leveraging a 7-degree-of-freedom Franka Emika robotic arm integrated with RF instrumentation, the system combines high-precision geometric and RF calibration, real-time collision-free path planning, and synchronized near-field and far-field power acquisition to perform hemispherical 3D scanning in non-anechoic environments. Achieving an angular resolution of 2.5°, the framework yields an average absolute error of <2 dB against full-wave simulations for a 60 GHz radar antenna—reducing error by 36.5% relative to baseline methods. The approach significantly enhances test flexibility, reusability, and repeatability.

Technology Category

• Intelligent Robots: Localization, Mapping, and Navigation
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Security and Privacy: Large-scale security measurements
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Accurate characterization of modern on-chip antennas remains challenging, as current probe-station techniques offer limited angular coverage, rely on bespoke hardware, and require frequent manual alignment. This research introduces RAPTAR (Radiation Pattern Acquisition through Robotic Automation), a portable, state-of-the-art, and autonomous system based on collaborative robotics. RAPTAR enables 3D radiation-pattern measurement of integrated radar modules without dedicated anechoic facilities. The system is designed to address the challenges of testing radar modules mounted in diverse real-world configurations, including vehicles, UAVs, AR/VR headsets, and biomedical devices, where traditional measurement setups are impractical. A 7-degree-of-freedom Franka cobot holds the receiver probe and performs collision-free manipulation across a hemispherical spatial domain, guided by real-time motion planning and calibration accuracy with RMS error below 0.9 mm. The system achieves an angular resolution upto 2.5 degree and integrates seamlessly with RF instrumentation for near- and far-field power measurements. Experimental scans of a 60 GHz radar module show a mean absolute error of less than 2 dB compared to full-wave electromagnetic simulations ground truth. Benchmarking against baseline method demonstrates 36.5% lower mean absolute error, highlighting RAPTAR accuracy and repeatability.

Problem

• Automates radar antenna radiation pattern measurement
• Eliminates need for dedicated anechoic facilities
• Enables testing in diverse real-world configurations

Innovation

• Portable robotic system for 3D radiation measurement
• 7-DOF cobot enables precise collision-free manipulation
• Real-time motion planning with sub-mm calibration accuracy