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Introduction
The RF Module is used by engineers and scientists to understand, predict, and
design electromagnetic wave propagation and resonance effects in high-frequency
applications. Simulations of this kind result in more powerful and efficient
products and engineering methods. It allows its users to quickly and accurately
predict electromagnetic field distributions, transmission, reflection, and power
dissipation in a proposed design. Compared to traditional prototyping, it offers
the benefits of lower cost and the ability to evaluate and predict entities that are
not directly measurable in experiments. It also allows the exploration of operating
conditions that would destroy a real prototype or be hazardous.
This module covers electromagnetic fields and waves in two-dimensional and
three-dimensional spaces along with traditional circuit-based modeling of passive
and active devices. All modeling formulations are based on Maxwell’s equations or
subsets and special cases of these together with material constitutive relations for
propagation in various media. The modeling capabilities are accessed via
predefined physics interfaces, referred to as Radio Frequency (RF) interfaces,
which allow you to set up and solve electromagnetic models. The RF interfaces
cover the modeling of electromagnetic fields and waves in frequency domain, time
domain, eigenfrequency, and mode analysis.
Under the hood, the RF interfaces formulate and solve the differential form of
Maxwell’s equations together with the initial and boundary conditions. The
equations are solved using the finite element method with numerically stable edge
element discretization in combination with state-of-the-art algorithms for
preconditioning and solution of the resulting sparse equation systems. The results
are presented using predefined plots of electric and magnetic fields, S-parameters,
power flow, and dissipation. You can also display your results as plots of
expressions of the physical quantities that you define freely, or as tabulated derived
values obtained from the simulation.
The work flow is straightforward and can be described by the following steps:
define the geometry, select materials, select a suitable RF interface, define
boundary and initial conditions, define the finite element mesh, select a solver, and
visualize the results. All these steps are accessed from the COMSOL Desktop. The
solver selection step is usually carried out automatically using default settings,
which are tuned for each specific RF interface.
The RF Module’s application library describes the physics interfaces and the
different features through tutorial and benchmark examples for the different
formulations. The library includes antennas, ferrite devices, microwave heating
phenomena, passive devices, scattering and RCS analysis, transmission lines and
