This article describes an implementation of a compact wire model into the three-dimensional transmission-line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe-coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages.

The transmission-line matrix method enhanced with the compact wire model in a cylindrical grid is used for modelling of a coaxially loaded cylindrical cavity resonator with probes inserted into the cavity. Benefits of using a cylindrical grid instead of rectangular, related to precise modelling of cavity boundaries, a coaxially shaped dielectric sample and radially placed wire elements, are explored. The accuracy of the simulated results is verified by measurements of an experimental model of the cavity-wire structure.

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A microwave applicator based on metallic cavity with a waveguide used to launch the energy from the source into the cavity is modelled using time-domain 3-D TLM method enhanced with model for modelling of wire and boundaries. An influence of waveguide length on EM field distribution inside the cavity is analyzed, in terms of modes presence and corresponding EM field levels.

Accurate near-field measurements for either deterministic or stochastic electromagnetic fields characterization require a relevant process that removes the influence of the probes, transmission lines, and measurement circuits. The main part of the experimental work presented here is related to a calibration procedure of a test setup consisting of a microstrip test structure and a scanning loop probe. The calibration characteristic, obtained by comparing measured and simulated results, is then used to convert the measured voltage into the magnetic field across and along the microstrip line at the specific height above it. By performing the measurements and simulations of the same test structure with the loop probe in the presence of an additional scanning probe, the influence of the additional probe to the measured output is thoroughly investigated and relevant corrections are given. These corrections can be important when two-point correlation measurement is required, especially in scanning points when two probes are mutually close.