COMSOL Blog

Calculate the Force of a One-Sided Magnet

Mark Fowler | March 21, 2014

When designing magnets, you want to save resources by using as little material as possible, while generating as large of a force as possible on the object in question. To calculate the force of a one-sided magnet, you can use COMSOL Multiphysics and the AC/DC Module.

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Modeling a Branch Line Coupler

Fanny Littmarck | March 14, 2014

Branch line couplers, a type of 90-degree or quadrature hybrid coupler, are popular because they are simple to fabricate and easy to design. They are passive devices commonly used in single-antenna transmitter systems and I/Q signal splitters/combiners. Let’s look at the basics of how this type of coupler works and some of its important design aspects.

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Benchmark Model Results Agree with Fresnel Equations

Lexi Carver | March 12, 2014

Have you ever wondered why boaters wear polarized sunglasses? It’s because sunlight reflecting off the water is primarily polarized in one direction, and polarized sunglasses will block this component of the reflected light, thus reducing glare. To understand why this is, we can use COMSOL software. This example solves the governing Maxwell’s equations using the RF Module or Wave Optics Module to simulate light incident at an angle upon a dielectric medium, and the solution shows agreement with analytic solutions.

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Plotting Spatial Derivatives of the Magnetic Field

Marc Fernandez Silva | March 5, 2014

Being able to compute the spatial gradients of the magnetic field or magnetic flux density is needed in areas such as radiology, magnetophoresis, and geophysics. One of the most important applications is in the design of magnetic resonance imaging machines, where it’s important to analyze not only the field strength, but also the spatial variation of the field. Today’s blog will demonstrate how to compute and plot the gradients of the magnetic field in 3D electromagnetic simulations in COMSOL Multiphysics.

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Reducing the Magnetic Signature of a Submarine

Mark Fowler | February 24, 2014

Submarines can be detected by enemy weapon systems due to their magnetic signatures. By designing vessels with reduced magnetic signatures, detection can be avoided, but the composition and size of most submarines often make simulation difficult. COMSOL software helps you overcome this problem.

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Piezoelectric Materials: Crystal Orientation and Poling Direction

Supratik Datta | February 14, 2014

The direct and inverse piezoelectric effects are strongly related to how anisotropic the material is, which in turn is related to the crystalline structure of the piezoelectric material. The extent of anisotropy can also be influenced by a process called poling. Here, I’ll discuss how you can correctly model the crystal orientation and poling direction of a piezoelectric material in your COMSOL simulations.

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Modeling Electromagnetic Waves and Periodic Structures

Walter Frei | January 17, 2014

We often want to model an electromagnetic wave (light, microwaves) incident upon periodic structures, such as diffraction gratings, metamaterials, or frequency selective surfaces. This can be done using the RF or Wave Optics modules from the COMSOL product suite. Both modules provide Floquet periodic boundary conditions and periodic ports and compute the reflected and transmitted diffraction orders as a function of incident angles and wavelength. This blog post introduces the concepts behind this type of analysis and walks through the […]

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Simulating an RF MEMS Switch

Lexi Carver | January 7, 2014

An RF MEMS switch is an electromechanical component found in RF systems. It usually consists of a micromechanical bridge or cantilever, a substrate, and an electrode or dielectric layer. These devices can switch at RF frequencies and tend to have high isolation, i.e. power loss when the switch turns off; low insertion loss (loss of signal power when the switch is on), and extremely low (almost zero!) power consumption. Let’s take a look at how you can use COMSOL Multiphysics […]

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Red Blood Cell Separation from a Flow Channel

Fanny Littmarck | January 3, 2014

Before conducting certain blood sample analyses, researchers need to separate the red blood cell particles from the blood plasma. Using lab-on-a-chip (LOC) technology, red blood cell separation can be achieved via magnetophoresis, i.e. motion induced by magnetic fields. Since the magnetic permeability of the particles is different from the blood plasma, their trajectory can be controlled within the flow channel of the LOC device and thereby separated out from the fluid.

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MEMS Microphone Model Presented at ASA 166 in San Francisco

Mads Herring Jensen | January 2, 2014

I recently had the pleasure of preparing a small contribution to the 166th Meeting of the Acoustical Society of America (Fall 2013) together with Wade Conklin and Jordan Schultz from Knowles Electronics. Wade presented our paper entitled “Characterization of a microelectromechanical microphone using the finite element method”. The work consisted of implementing a virtual prototype of a Knowles MEMS microphone (the SPU0409LE5H microphone, see picture below) using COMSOL Multiphysics.

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The Linac-MR Project: Tumor Tracking and Treatment

Alexandra Foley | December 30, 2013

Not too long ago, my colleague Jennifer wrote a blog post about the Cross Cancer Institute, and the research being conducted there into the design of a new device for treating cancerous tumors. The device, known as the Linac-MR, is revolutionary due to its ability to both image and treat cancer cells simultaneously — a capability that had previously been regarded as near impossible due to the conflicting physics interactions involved. Such a device would allow for extremely precise radiation […]

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