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. 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.
Multipaction can occur when electrons are accelerated by a high frequency RF field into surfaces. At certain frequencies, the number of electrons in a cavity can grow exponentially. This exponential growth cannot continue indefinitely because space charge effects in the cavity can ... Read More
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 ... Read More
This model shows how to model a simple Shockley diode— a four-layer PNPN semiconductor device. The Shockley diode is also named as thyristor. In this model, the Analytic Doping Model node is utilized to define the doping profiles for each domain. A time-dependent study is employed to ... Read More
This tutorial model presents a study showing the transient negative mobility and the negative differential conductivity effects in xenon. The stationary and time dependent Boltzmann equation in the two-term approximation is used to compute the electron energy distribution function. ... Read More
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 ... Read More
While transient analyses are useful for time domain reflectometry (TDR) to handle signal integrity (SI) problems, many RF and microwave examples are addressed using frequency domain simulations generating S-parameters. However, from the frequency domain data it is difficult to identify ... Read More
An evanescent mode cavity filter can be realized by adding a structure inside of the cavity. This structure changes the resonant frequency lower than the dominant mode of the unfilled cavity. A piezo actuator is used to control the size of a small air gap which provides the tunability of ... Read More
This tutorial example shows how to set port features in a physics interface when designing a grounded coplanar waveguide (GCPW) circuit that is useful for mmWave applications. Read More
This model solves the Boltzmann equation in two-term approximation for a mixture of nitrogen and oxygen representing a background gas of dry air. Electron transport coefficients and source terms are computed by suitable integration of the electron energy distribution function over ... Read More
An anechoic chamber is used to measure antenna characterization, electromagnetic interference (EMI), and electromagnetic compatibility (EMC). Within the chamber are absorbers that are configured with an array of pyramidal objects that steer the propagating incident field onto their ... Read More