Accurate Characterization of High-$Q$ Microwave Resonances for Metrology Applications

Abstract

Microwave resonators are widely adopted as high sensitivity sensors in both applied and fundamental metrology, to measure a number of different physical quantities, such as temperature, humidity, pressure, length and material properties. High sensitivity, and thus potential high measurement precision and accuracy, can be achieved by resorting to high-quality-factor (Q) resonators. Nonetheless, in order to accurately measure a high-Q resonance and obtain low measurement uncertainty, as required by metrology applications, the entire measurement set-up must be carefully designed. This papers presents an overview of resonance frequency measurements for metrology applications, illustrating the various aspects and issues to be dealt with when pursuing highly accurate measurements, as well as of the most relevant achievements in this field.

Permittivity measurement of fluidics with high‐sensitivity by chandelier form microwave sensor

“…Three samples of sheep, chicken, and fish meats were chosen as samples. In Ramella et al, 61 the relative permittivity of three samples of 1‐day postmortem time of sheep, chicken, and fish, were obtained as 48, 50, and 52, respectively. illustrates the S21‐diagram for samples of fresh meat from three animals.…”

Development, Characterization, and Circuit Modeling of Inkjet-Printed Coupled Ring Resonators for Application in Biological Samples

“…The developed software draws out the two Lorentzian complex functions from the acquired S 21 parameter and, for each Lorentzian function, the software returns the best estimation of the resonant frequency, the Q-factor, and the resonant-peak amplitude. The fitting process is essential in this case since the two resonant peaks in the magnitude of the transmission coefficient are coupled with each other, and their overlap may result in an inaccurate evaluation of the main resonant parameters (i.e., f r and Q) [41]. The double-Lorentzian fitting is illustrated in Fig.…”

A symmetric bar chart-shape microwave sensor with high Q-factor for permittivity determination of fluidics

“…The high precision and accuracy of sensors and easy to handle have made them useful in various fields such as food [1] and pharmaceutical [2] industries. Sensors can be combined with applications such as the internet of things [3, 4] and metrology [5]. Sensors have several interesting applications, for example, when snow falls on antennas of base stations, they can detect snow and its quantity and then they can activate a system for melting snow [6].…”