Near-field open coaxial sensor. Measurement aperture spatial resolution ability evaluation

Abstract

Microwave sensors find wider and wider application in the different domain. The sensors design became more complicated, the methods of their description became more exact.The paper presents a simplified model for describing the near field of a coaxial sensor. There was given grounding of analytical solution simplification, considered fields components in the working area and analyzed field in the working area distribution. The results of a comparison of the distributions of the electromagnetic field components near the aperture are shown, obtained on the basis of a rigorous and simplified model. The field intrusion into the sample at first approximation corresponds to radial distribution. The spatial resolving ability of the sensor, both along the radius and the depth of the sample, is determined by the diameter of the central conductor or by the size of the slit. By varying the shape of the aperture, it is possible to change the characteristics of the sensor, optimally selecting them for a priori known properties of the sample.