Microwave Heating of a Cancer Tumor
Electromagnetic heating is ideally suited for modeling in COMSOL Multiphysics. This model shows the area of hyperthermic oncology but the modeling issues and techniques are generally applicable to any problem involving electromagnetic heating. The purpose of this model is to compute the radiation field and the Specific Absorption Rate (SAR) in liver tissue for a thin coaxial slot antenna used ...
RF Heating
This is a model of an RF waveguide bend with a dielectric block inside. There are electromagnetic losses in the block as well as on the waveguide walls which cause the assembly to heat up over time. The material properties of the block are functions of temperature. The transient thermal behavior, as well as the steady-state solution, are computed.
H-Bend Waveguide 3D
These examples show how to model a rectangular waveguide for microwaves in 2D and 3D. A single hollow waveguide can conduct two kinds of electromagnetic waves: transversal magnetic (TM) or transversal electric (TE) waves. The models examine a TE wave that has no electric field component in the direction of propagation. More specifically, for the models, you select the frequency and ...
Radar Cross Section
This tutorial model demonstrates the use of a background field in an electromagnetic scattering problem. Although this example is a boat hit by a radar, this same technique can be used in any situation where an isolated object meets electromagnetic waves from a distant source. For example, several orders of magnitude smaller, an equally common application is plasmon resonant nanoparticles. ...
Microwave Oven
This is a model of the heating process in a microwave oven. The distributed heat source is computed in a stationary, frequency-domain electromagnetic analysis. This is followed by a transient heat transfer simulation showing how the heat redistributes in the food.
Modeling of Pyramidal Absorbers for an Anechoic Chamber
In this model, a microwave absorber is constructed from an infinite 2D array of pyramidal lossy structures. Pyramidal absorbers with radiation-absorbent material (RAM) are commonly used in anechoic chambers for electromagnetic wave measurements. Microwave absorption is modeled using a lossy material to imitate the electromagnetic properties of conductive carbon-loaded foam.
Coplanar Waveguide Bandpass Filter
Coplanar waveguide (CPW) bandpass filters can be designed using interdigital capacitors (IDCs) and short-circuited stub inductors (SSIs). This is a very efficient manufacturing method for producing bandpass filters, which can readily be implemented on a GaAs wafer. The Coplanar Waveguide Bandpass Filter tutorial model presents a design that is compact in relation to its resonant frequency and ...
Waveguide Adapter
This is a model of an adapter for microwave propagation in the transition between a rectangular and an elliptical waveguide. Such waveguide adapters are designed to keep energy losses due to reflections at a minimum for the operating frequencies. To investigate the characteristics of the adapter, the simulation includes a wave traveling from a rectangular waveguide through the adapter and into ...
Frequency Selective Surface Simulator
Frequency selective surfaces (FSS) are periodic structures that generate a bandpass or a bandstop frequency response. They are used to filter or block RF; microwave; or, in fact, any electromagnetic wave frequency. For example, you see these selective surfaces on the doors of microwave ovens, which allow you to view the food being heated without being heated yourself in the process. The ...
Computing the Radar Cross Section of a Perfectly Conducting Sphere
A classic benchmark problem in computational electromagnetics is to solve for the radar cross section (RCS) of a sphere in free space illuminated by a plane wave. This model solves for the RCS of a metallic sphere that has a very high conductivity, which can be treated as a material with infinite conductivity. Results are compare to the analytic solution, and agreement is shown.
