The Application Gallery features COMSOL Multiphysics® tutorial and demo app files pertinent to the electrical, structural, acoustics, fluid, heat, and chemical disciplines. You can use these examples as a starting point for your own simulation work by downloading the tutorial model or demo app file and its accompanying instructions.

Search for tutorials and apps relevant to your area of expertise via the Quick Search feature. To download the MPH-files, log in or create a COMSOL Access account that is associated with a valid COMSOL license. Note that many of the examples featured here can also be accessed via the Application Libraries that are built into the COMSOL Multiphysics® software and available from the File menu.

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Log-Periodic Antenna

The shape of a log-periodic antenna resembles that of a Yagi-Uda antenna, but is composed of a coplanar array to achieve a wider bandwidth. It is also known as a wideband or frequency-independent antenna. All metallic parts are modeled using the perfect electric conductor (PEC) boundary conditions. The antenna is excited by a lumped port while a lumped element with a resistor is used to ...

Transmission Line Butler Matrix Beamforming Network

A Butler matrix is a passive beamforming feed network. It is a cost-effective feed network for phased array antennas because the circuit can be fabricated in the form of microstrip lines and is a viable solution for performing beam scanning without deploying expensive active devices. This example shows how to design such a circuit using the *Transmission Line* interface. The results show the ...

Double-Ridged Horn Antenna

A double-ridged horn antenna is popularly used in anechoic chambers to characterize an antenna under test (AUT), from S-band to Ku-band, due to its reliable performance in a wideband frequency range. This tutorial models a double-ridged horn antenna and computes the voltage standing wave ratio (VSWR), far-field radiation pattern, and antenna directivity. A lumped port is assigned on the ...

Rat-Race Coupler

A 180° Ring Hybrid (Rat-Race Coupler) is a four-port network with 180° phase difference between two ports. It is cheaper to manufacture this type of microstrip line component compared to a wave guide 180° hybrid junction, so called magic-T. The objective of this model is to compute the S-parameters and to observe the matching, isolation, and coupling around the operating frequency.

Time-Domain Modeling of Dispersive Drude-Lorentz Media (RF)

This tutorial shows how to solve the full time-dependent wave equation in dispersive media such as plasmas and semiconductors. The 2D TM in-plane wave model solves for the vector potential from the wave equation and for an auxiliary electric polarization density from an ordinary differential equation. The geometry consists of a single dispersive slab with a sub-wavelength slit in it. Periodic ...

Radome with Double-layered Dielectric Lens

A radome minimizes losses and improves radiation characteristics of an antenna through its design. The structure can be optimized to minimize the transmission loss and also designed to improve radiation characteristics including antenna directivity and side lobes. Shown in the model is the surface current density on the patch antenna, the magnitude of the electric potential on the antenna's ...

Time-to-Frequency Fast Fourier Transform of a Coaxial Low-Pass Filter

A very wide band coaxial low-pass filter is designed using a 2D axisymmetric model. To address the wide band frequency response with a fine frequency resolution, the model is built with a transient physics interface first. Then, S-parameters are calculated using a time-to-frequency Fourier transform. To achieve a low-pass frequency response, an air-filled coaxial cable is tuned with five ...

Car Windshield Antenna Effect on a Cable Harness

Modern cars have rear-windshield FM antennas to play FM radio. The radiation emitted from an antenna induces an electric current on the outer surface of any cable harnesses in the car, which can have negative effects. This model uses the RF Module to compute the far-field radiation pattern of the antenna, by enclosing the car in perfectly matched layers separated by an air domain. The electric ...

Modeling a Conical Dielectric Probe for Skin Cancer Diagnosis

The response of a millimeter wave with frequencies of 35 GHz and 95 GHz is known to be very sensitive to water content. This model utilizes a low-power 35 GHz Ka-band millimeter wave and its reflectivity to moisture for non-invasive cancer diagnosis. Since skin tumors contain more moisture than healthy skin, it leads to stronger reflections on this frequency band. Hence the probe detects ...

Antenna Decoupling Using An Electromagnetic Band Gap Meta-Material

An Electromagnetic Band Gap (EBG) structure can be used to increase the isolation between antennas close to each other. The decoupling effect is not only a function of frequency but also polarization and coupling-plane configuration. When designing an EBG structure, one needs to make sure to not apply an incorrect frequency and polarization, since this would increase the coupling between ...