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 ...

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 ...

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.

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.

Dipole Antenna with a Quarterwave Coaxial Balun (1:1)

An antenna balun blocks undesirable currents on the outside of a cable. A quarter-wave coaxial balun (1:1) is one of the easiest designs: it works as a transformer and makes the input impedance from the inner conductor to the outer conductor infinite. This model simulates an antenna prototype including a SMA Receptacle, an ABS enclosure and a quarter-wave coaxial balun. The frequency is tuned to ...

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.

Two Arm Helical Antenna

A helical antenna has two major modes. One is normal mode and the other is axial mode. When the helical antenna is operating at the normal mode, its far-field radiation pattern is similar to the torus shaped pattern of a classic dipole antenna. At the axial mode, the helical antenna is resonant at a much higher frequency band than the normal mode operation, and works similarly to an end-fire ...

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.

Biconical Antenna

A Biconical antenna is a type of wideband antenna with omni-directional radiation pattern in the H-plane similar to a dipole antenna. A coaxial feed is connected to the radiators using two 90 degree bent arms. The model shows that the biconical antenna works well in applications requiring an omnidirectional radiation pattern and wide bandwidth.

Substrate Integrated Waveguide

A waveguide-type structure can be fabricated on a substrate by adding vias between the microstrip line and the ground plane. Such a device will behave as a high-pass filter and is attractive because it is easy to fabricate. A model is set up that shows the S-parameters as a function of frequency. A sharp cutoff is shown at the expected frequency.

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