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.

Three-Port Ferrite Circulator

A microwave circulator is a multiport device in which a wave incident on Port 1 is coupled only into Port 2; a wave incident on Port 2 is coupled only into Port 3; and so on. Circulators are used to isolate microwave components, for example, to couple a transmitter and a receiver to a common antenna. They typically rely on anisotropic materials, most commonly ferrites. This model simulates the ...

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 ...

Conical Antenna

Conical antennas are useful for many applications due to their broadband characteristics and relative simplicity. In this example, we study the antenna impedance and radiation pattern as functions of frequency for a monoconical antenna with a finite ground plane and a 50 ohm coaxial feed. The rotational symmetry allows us to model in 2D, using one of the axisymmetric electromagnetic wave ...

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.

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.

Fabry-Perot Cavity

This is an example of a Fabry-Perot cavity, the simplest optical resonator structure. It is a classical problem in optics and photonics. Two methods are shown for computing the Q-factor. The losses in this model are purely via radiation away from the resonator.

Connecting a 3D Electromagnetic Waves Model to an Electric Circuit

A model built with the RF Module can be connected to an electrical circuit equivalent, if there is some structure outside of the model space that you wish to approximate as a circuit equivalent. In this model, the 3D model of a coaxial cable is connected to a voltage source, in series with a matched impedance, and sees a load, also of matched impedance.

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.

Finding the Impedance of a Parallel-Wire Transmission Line

A parallel wire transmission line is composed of two conducting wires in a dielectric such as air. The fields around such a transmission line are not directly confined by the conductors, and extend to infinity, although they drop off in rapidly away from the wires. This model demonstrates how to compute the fields and impedance of such an unshielded transmission line, and compares to the analytic ...

Branch Line Coupler

A Branch Line Coupler (Quadrature 90° Hybrid) is a four-port network device with a 90° phase difference between two coupled ports. The device can be used for a single antenna Transmitter/Receiver system or an I/Q signal splitter/combiner. The objective of this model is to compute the S-parameters and to observe the matching, isolation, and coupling around the operating frequency.

Quick Search