Electrical

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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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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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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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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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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Daniel Smith | December 11, 2013

Microwave plasmas, or wave-heated discharges, find applications in many industrial areas such as semiconductor processing, surface treatment, and the abatement of hazardous gases. This blog post describes the theoretical basis of the Microwave Plasma interface available in the Plasma Module.

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Magnus Olsson | December 2, 2013

When designing inductive devices, both challenges and possibilities are associated with the nonlinear behavior of ferromagnetic materials. COMSOL Multiphysics is well-adapted to the solution of highly nonlinear numerical models but high-fidelity modeling of nonlinear inductive devices also requires accurate material data. To meet this challenge, a library of 165 nonlinear magnetic materials is provided in COMSOL 4.4, bringing new powers to the design and modeling of electric motors, transformers, relays, etc. Here, we will discuss how the modeling process is […]

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Fanny Littmarck | November 8, 2013

There were many interesting posters at this year’s COMSOL Conference in Boston. A couple that caught my eye involved microwave heating and chemical applications. One of them showcases the use of microwave irradiation to speed up chemical reactions. Another — one of the recipients of the Best Poster award — used simulations to optimize their microreactor design with respect to microwave propagation.

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Alexandra Foley | October 11, 2013

A Wilkinson power divider is a common three-port power splitter circuit that is used to split an input signal into two equal output signals, or to combine two signals into one. Unlike resistive or T-junction power dividers, a Wilkinson power divider allows for nearly complete isolation between the two ports and adds no resistive losses to the power split. Because of these characteristics, a Wilkinson divider is widely used in radio communication systems due to its ability to prevent crosstalk […]

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Fanny Littmarck | October 8, 2013

A Gaussian beam that is striking an array of nanorods is an example of optical scattering. Consider metallic nanorods that are very close together and have a diameter much smaller than the wavelength of a Gaussian beam that falls upon them. If the beam were to be polarized along the rods, they would act as though they were not actually individual rods, but a sheet of metal. The array is nearly transparent to the wave when it is polarized perpendicular […]

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Supratik Datta | September 25, 2013

If you are using a cell phone, GPS, Bluetooth, or WiFi, chances are that they all have BAW resonators working inside them. All wireless electronic equipment use RF filters to help narrow down the frequency range they should operate within. With thousands of devices working within closely-packed radio frequencies, it is becoming increasingly important to design filters that would be able to reduce interference from unwanted frequencies, boost the signal-to-noise ratio, and lower insertion loss. Doing so may lead to […]

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