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.

Coupled-Line Bandpass Filter

It is possible to realize a narrowband bandpass filter using cascaded microstrip coupled lines. In this example, a design composed of cascaded microstrip lines, each approximately a half wave length in size at the resonant frequency, is analyzed. The model is solved for the S-parameters and a very narrow bandwidth is observed.

Sierpinski Fractal Monopole Antenna

A fractal is a mathematical form showing self-repeating patterns. By virtue of its geometrical properties, a fractal structure can generate multiple resonances in RF applications. This antenna model uses a 3rd order Sierpinski triangle and the calculated S-parameters shows good input matching at the higher order resonances.

A Low-Pass Filter Using Lumped Elements

Low frequency devices can be designed using lumped element features if both the operating frequency of the device and the insertion loss are low. In this model, a 5-element maximally low-pass filter is simulated. The resulting S-parameter show the cutoff at the intended frequency.

Evanescent Mode Cylindrical Cavity Filter

An evanescent-mode cavity filter is resonant at a frequency lower than its original fundamental mode frequency. Evanescent mode resonance can be realized by creating a discontinuity or reactance inside the cavity. The basic model was modified by the addition of a metal box at either end representing a housing. Inside a dielectric substrate and a microstrip line coupled into the cavity. The ...

Circularly Polarized Antenna for the GPS Applications

One way to generate circular polarization from a microstrip patch antenna is to truncate the patch radiator. This model is tuned around the GPS frequency range. The axial ratios are calculated to show the degree of circular polarization.

Simulation of an Electromagnetic Sounding Method for Oil Prospecting

The marine controlled source electromagnetics method (CSEM) for oil prospecting has emerged as a promising technique during recent years. This model demonstrates one variant of it. It uses a mobile horizontal 1 Hz electric dipole antenna that is towed 150 m above the sea floor. An array of sea floor receivers measure the electric field at various distances away from the antenna. When measuring ...

Thermal Drift in a Microwave Filter Cavity

Microwave filters are used to eliminate unwanted frequency components in the output from microwave transmitters. They are typically inserted between a power amplifier and an antenna. The amplifiers are nonlinear and produce harmonics that must be eliminated with filters that have a rather narrow passband. Due to high power loads but also possibly from harsh environmental conditions (such as a ...

Cascaded Rectangular Cavity Filter

A cascaded cavity filter provides much better bandpass filter performance compared to a single cavity. Out-of-band rejection improves dramatically using a cascaded design. This model uses three rectangular cavity filters coupled via slots. The calculated S-parameters show excellent out-of-band rejection.

Circular Waveguide Iris Bandpass Filter

A circular waveguide filter is designed using a 2D axisymmetric model. Six annular rings added to the waveguide form circular cavities connected in series, and each cavity cutoff frequency is close to the center frequency of the filter. The simulated S-parameters show a bandpass frequency response.

Axisymmetric Cavity Resonator

This is a benchmark model for the 2D axisymmetric formulation of the Electromagnetic Waves, Frequency Domain interface that is available with the RF Module. The problem is to find the resonant frequencies and fields inside an axisymmetric cavity with rectangular cross-section and perfectly conducting walls. Analytical expressions for the eigenvalues can be obtained using separation of variables. ...

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