A LabVIEW application for the characterization of high-frequency resonant sensors using a software-defined radio platform

Abstract

Microwave resonant sensors have been extensively employed in a wide range of applications. This sensor is generally used to infer a specific parameter of interest by means of its resonance frequency, and it is designed taking into account the boundary conditions of each application. After the implementation, a Vector Network Analyzer (VNA) is generally used to validate and compare the simulated and experimental results. VNAs are ex-pensive instruments, hence, low-cost alternatives, such as portable VNAs, can also be used, although these instruments generally run over limited applications. On the other hand, Software-Defined Radio (SDR) platforms have been used in several applications, beyond their common employment in communication systems. In this work is presented a detailed procedure to implement a LabVIEW application for the characterization of high-frequency resonant sensors using an SDR platform. The application was able to extract the magnitude and phase information from a resonant cavity sensor, demonstrating that it can also serve as a basis for the implementation of more sophisticated routines, with few modifications.