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.

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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.

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.

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 ...

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 ...

Parabolic Reflector Antenna

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

Circularly Polarized Antenna for 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.

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 ...

Branch-Line Coupler

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-parameters and to observe the matching, isolation, and coupling around the operating frequency.

Fast Numerical Modeling of a Conical Horn Lens Antenna

An axisymmetric 3D structure such as a conical horn antenna can be simulated in a fast and efficient way using only its 2D layout. In this model, the antenna radiation and matching characteristics are computed very quickly with respect to the dominant TE mode from the given circular waveguide by simulating the 2D axisymmetric geometry of an 3D antenna structure.

Designing a Waveguide Diplexer for the 5G Mobile Network

A diplexer is a device that combines or splits signals into two different frequency bands, widely used in mobile communication systems. This model simulates splitting properties using a simplified 2D geometry. The computed S-parameters and electric fields at the lower and upper bands will show the diplexer characteristics in the Ka-band.