Model Gallery

The Model Gallery features COMSOL Multiphysics model files from a wide variety of application areas including the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use models and step-by-step instructions for building the model, and use these as a starting point for your own modeling work. Use the Quick Search to find models relevant to your area of expertise, and login or create a COMSOL Access account that is associated with a valid COMSOL license to download the model files.

Lossy Circular Waveguide

In mode analysis it is usually the primary goal to find a propagation constant. This quantity is often, but not always, real valued; if the analysis involves some lossy part, such as a nonzero conductivity or an open boundary, the eigenvalue is complex. In such situations, the real and imaginary parts have separate interpretations: The real part is the propagation constant The imaginary part is ...

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.

Step Index Fiber

The transmission speed of optical waveguides is superior to microwave waveguides, because optical devices have a much higher operating frequency than microwaves, enabling a far higher bandwidth. This model is an example of a single step-index waveguide made of silica glass. The inner core is made of pure silica glass with refractive index n1 = 1.4457 and the cladding is doped, with a refractive ...

Feasibility Study of Microstrip Patch Antenna Array Design

An antenna array is a group of radiating elements. By controlling the phase and magnitude of the input signal assigned to each antenna element and the number of array elements, the radiation pattern can be steered in a desired direction with a preferred level of gain. In this example, a 4 x 2 array of patch antennas is fed from a single feed point, with all elements fed at equal phase and ...

Second Harmonic Generation of a Gaussian Beam

Laser systems are an important application area in modern electronics. With nonlinear materials it is possible to generate harmonics that are a multiple of the frequency of the laser light. This model shows how a second harmonic generation can be set up as a transient wave simulation, using nonlinear material properties. A YAG (lambda=1.06 microm.) laser beam is focused on a nonlinear ...

Transient Modeling of a Coaxial Cable

Simulation of Maxwell’s equations in the time domain is useful if the objective of the analysis is to observe a transient phenomenon, to find the time it takes a signal to propagate, or if the materials being modeled are non-linear with respect to the electric or magnetic field strength. This model simulates a pulse propagating down a coaxial transmission line and observes the time it takes for ...

Dielectric Slab Waveguide

A planar dielectric slab waveguide demonstrates the principles behind any kind of dielectric waveguide such as a ridge waveguide or a step index fiber. This model solves for the effective index of a dielectric slab waveguide, as well as the fields, and compares to analytic results.

Vivaldi, Tapered Slot Antenna (TSA)

A tapered slot antenna, also known as a Vivaldi antenna, is useful for wide band applications. Here, an exponential function is used for the taper profile. The objective of this model is to compute the far-field pattern and to compute the impedance of the structure. Good matching is observed over a wide frequency band.

SMA Connector on a Grounded Coplanar Waveguide

SMA connectors are popularly used on printed circuit boards (PCB) for testing. This model shows how to excite an SMA connector on a microwave substrate and how to terminate a grounded coplanar waveguide (GCPW) with 50 ohm using a lumped port and an air-bridge.

Wilkinson Power Divider

Some conventional three-port power dividers are resistive power dividers and T-junction power dividers. Such dividers are either lossy or not matched to the system reference impedance at all ports. In addition, isolation between two coupled ports is not guaranteed. The Wilkinson power divider outperforms the lossless T-junction divider and the resistive divider and does not have the issues ...

Quick Search