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.
Passive devices can be designed using lumped element features if both the operating frequency of the device and the insertion loss of lumped elements are low. This example simulates two types of lumped element filters that are similar to lumped ports, except that they are strictly ... Read More
A large reflector can be modeled easily with the 2D axisymmetric formulation. In this model, the radius of the reflector is greater than 20 wavelengths and the reflector is illuminated by an axial feed circular horn antenna. The simulated far-field shows a high-gain sharp beam pattern Read More
A conductive diaphragm, an iris, placed transverse to a waveguide aperture causes a discontinuity and generates shunt reactance. Bandpass frequency response can be achieved from cascaded cavity resonators combined with these reactive elements which can be created by inserting a series of ... Read More
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 ... 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
This model uses the Semiconductor and RF modules to describe a photoconductive antenna (PCA). A laser pulse is applied on the surface of undoped LT-GaAs to generate electron-hole-pairs, which move under the influence of an external E-field creating a transient electric current pulse. ... Read More
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 ... Read More
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 ... Read More
In signal integrity (SI) applications, time-domain reflectometry (TDR) is a useful technique for analyzing the discontinuity in a signal path by observing the reflected signal strength. The reflected signal distorts the input pulse mainly by impedance mismatch if there is no external ... Read More
This Application Gallery entry demonstrates how Far-Field radiation can be calculated when a substrate is present. Two approaches are demonstrated. A simplified form that works for two homogeneous domains, and a general approach that can handle multiple, inhomogeneous layers. This ... Read More