Coaxial Cable-Based Near-Field Probing for Plant Stem Monitoring Using Millimeter Waves

This paper presents a calibration method for near-field probes (NFPs) based on the reaction theorem to determine the probe coefficient and isolation. These parameters are essential for optimizing the probe’s performance in plant stem monitoring. By integrating the calibrated NFP into a cylindrical positioning setup, the reconstruction of the internal structure of plant stems can be realized by fitting measured and simulated near-field data. Bamboo stem, due to its simple and rigid geometric properties, can serve as an initial test subject to validate the feasibility of the proposed approach.