On the Effects of Industrial Robotic Arms on the Pattern of the Probe for Near-Field Measurements

Authors: Vince Rodriguez, Mark Ingerson, Gwenael Dun, Esra Celenk
Publication: AMTA 2025
Copyright Owner: NSI-MI Technologies

The first mention of a Robot for near-field measurements of antennas appears is by Jeff Snow in [1]. This was a simple robotic arm to do planar measurements. About 7 years later, the use of off-the-shelf industrial robotic arms for doing antenna measurements is introduced [2]. Since then, industrialrobot- arm based antenna measurement systems have become increasingly popular due to their flexibility to measure over different surfaces allowing the system to do planar, spherical and cylindrical. The use of other methods to perform the transform, by numerically compute the currents on an arbitrary surface from the measured fields has helped in the growing popularity of robotic systems. This is related that the measurement surface does no longer have to be a canonical surface but can be any shape. However, the flexibility of the robots may be limited by the RF absorber coverage used in treating them. In this paper, the authors explore the potential scattering from the robotic arm in different positions and its effect on the probe illuminations. This is an area of research on the use of absorber that has not been explored until recently [3]. Numerical experiments are conducted to explore the effects of RF absorbers in the 300 MHz to 3 GHz range. Open ended waveguides (OEWG) as well as dual ridged horns (see Figure 1) are used as the probes. The results suggest that some areas of the arm need to be treated while others can be left bare. The analyses performed suggest that optimized treatment of robotic arms to maintain the flexibility of the technique while also reducing effects on the probe illuminations are possible.

View the paper