Study of Spectra with Low-Quality Resonance Peaks

摘要

A Python-based software for the phenoCAVe family of resonators for plants investigations is developed to automatically extract both the center frequency and the quality factor of the main resonance peak, i.e., of the lowest transversal-magnetic mode TM_(010), at different scan positions. Due to the specific design of the cavities, which includes large openings on the top and on the bottom of the resonators, the main peak even in the unloaded case (when no object is measured) has a sufficiently small quality factor (<350), which leads to the large influence of the higher modes on the reliability of the extracted data. Additionally, the repeated movements of the resonators and long cables usage may alter the cable influence. Moreover, continuous movements during the scans as well as a finite time of spectra sweep give a distorted peak, especially at the borders of large objects, such as plant pots, i.e., when the objects are starting to pass through a resonator. All these problems and more are taken into account in the automatic data analysis software, which allows to obtain reliable responses from noninvasive scans of the investigated plants over the whole period of their growth and further usage of these responses to calculate the important parameters for the plant growth, such as water content, dry weight, biomass, pot water content etc. Here, the whole process from the analysis of distorted spectra to the evaluation of the suitable parameters for plant growth is demonstrated. Such an analysis can be used not only for plant phenotyping platforms but also in various physical platforms supposing low-quality spectra analysis and dielectric studies of materials.