Efficient integral cylindrical transmission‐line matrix modelling of a coaxially loaded probe‐coupled cavity

Abstract

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.

Computational Modeling of the Bent Antenna in an On-Body Mode Using the Cylindrical TLM Approach

“…e iterative procedure of the TLM algorithm consists of two main procedures known as the scattering and the connection [14]. ey are adjusted to the orthogonal polar mesh and are additionally modified to account for excitation, boundaries, and inhomogeneous medium and losses [18,19].…”

“…An adaptation and implementation of the compact wire model to the cylindrical grid [18] has enabled representation of the wires placed along the radial direction. e connection procedure has had to be appropriately adjusted to describe a straight wire segment located along the radial direction as described in [18,19]. Impedances of link lines and a stub, which are embedded into the existing network of cells to account for the wire, are different for adjacent nodes k and k + 1:…”

Transmission Line Modelling of an Eccentrically Loaded probe Coupled Cylindrical Cavity

“…Application of this method for modeling of resonant probe-coupled loaded cavities provides better understanding of the mode tuning behavior in the cavity under loading condition and feeding/monitoring coupling mechanism, allowing users to make necessary changes to optimize the microwave design [1][2][3][4][5][6]. The precise modelling of physical and electrical parameters of a cavity load is of particular interest in microwave heating and biomedical applications [2][3][4][5][6][7]. A cylindrical cavity loaded with a concentric dielectric cylinder represents a very suitable model used to study various materials in microwave heating and biomedical applications based on hyperthermia treatment [2,7].…”

“…The precise modelling of physical and electrical parameters of a cavity load is of particular interest in microwave heating and biomedical applications [2][3][4][5][6][7]. A cylindrical cavity loaded with a concentric dielectric cylinder represents a very suitable model used to study various materials in microwave heating and biomedical applications based on hyperthermia treatment [2,7]. Particularly, the eccentrically loaded cylindrical cavity is considered to determine variation in the frequency if the load is not positioned at the cavity centre and also to investigate localized heating spots [2].…”

“…It allows modelling of signal propagation along the wire and the two-way interaction between the electromagnetic field and the wire, while taking into account physical dimensions of the wire probes which can be much smaller than the node size and hence limited only by the mesh resolution [12]. However, as it is explored in [7], when the cubic mesh which uses this compact wire model is applied to a probe-coupled cylindrical cavity resonator, with probes placed along the radial direction, in order to satisfy the requirement of applying the mesh of higher resolution to achieve more precise modelling of boundaries it is necessary to use the probe radius that is significantly smaller than the physical one since it must be at least 4 times smaller than the cross-section size of TLM nodes through which the wire propagates [12]. As a result, the maximum probe radius that could be used is limited [7,9,11].…”