A study on coaxial line excited monopole probes for in situ permittivity measurements

A coaxial line excited monopole probe has attracted many researchers for in situ permittivity measurement of materials. In most of these cases, a delta gap excitation is assumed for the probe in relating the measured input impedance to the permittivity of the material. Since an open-ended coaxial line is more accurately represented by a magnetic frill generator, we employed this model of excitation for the present study. This paper reports the results obtained by solving the Pocklington´s integral equation numerically using a magnetic frill excitation and piecewise sinusoidal Galerkin method. A comparison of these results with the available experimental and theoretical data is presented and some limitations of this approach are discussed.