Predict Thermal Drift in Microwave Filters Using Multiphysics Simulation

Caty Fairclough April 11, 2017

Microwave filters can help prevent unwanted frequency components in the output of a microwave transmitter design. However, when the microwave system experiences thermal drift, it can be difficult to achieve high-frequency stability in the filters. To address this issue and improve filter designs, system engineers need to predict the change of the passband frequency caused by thermal expansion. As we’ll see today, one way to achieve this is with multiphysics modeling.

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Caty Fairclough March 24, 2017

Magnetic resonance imaging (MRI) systems must produce high-resolution images in order for doctors to accurately diagnose their patients. To achieve this level of image quality, there must be a known reliable base magnetic field distribution within the MRI machine and its components, such as birdcage coils. This is where simulation comes in. By designing MRI birdcage coils with the COMSOL Multiphysics® software, we can manipulate and optimize the magnetic field and improve the scanned data that MRI machines generate.

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Bridget Cunningham March 21, 2017

Exposure to the environment can negatively impact an antenna’s radiation characteristics and lead to greater losses. One way to protect these devices is with radomes, which are enclosures that can shield antennas while improving their overall performance. When designing a radome, measuring its effectiveness is key, as designs without optimized configurations have less influence. With the example of a patch antenna, we discuss using simulation to gain insight into a radome’s ability to improve antenna directivity.

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Bridget Cunningham March 13, 2017

Noncommunicable diseases place a socioeconomic strain on low- to middle-income countries. The advent of noninvasive technology offers a solution, effectively diagnosing, preventing, and treating these diseases at a lower cost. For chronic kidney disease, one type of noncommunicable disease, such advancements are important because current methods are expensive and prone to error. As simulation research shows, sensors based on complementary split ring resonators (CSRRs) provide an inexpensive way to accurately monitor chronic kidney disease.

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Andrew Strikwerda January 30, 2017

Welcome back to our discussion on multiscale modeling in high-frequency electromagnetics. Multiscale modeling is a simulation challenge that arises when there are vastly different scales in a single simulation, such as the size of an antenna compared to the distance between the antenna and its target. Today, in Part 4 of the series, we will examine how we can construct a multiscale model by coupling a Full-Wave antenna simulation with a geometrical optics simulation using the Ray Optics Module.

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Andrew Strikwerda January 18, 2017

In Part 3 of our series on multiscale modeling in high-frequency electromagnetics, let’s turn our attention to the receiving antenna. We’ve already covered theory and definitions in Part 1 and radiating antennas in Part 2. Today, we will couple a radiating antenna at one location with a receiving antenna 1000 λ away. For verification, we will calculate the received power via line-of-sight transmission and compare it with the Friis transmission line equation that we covered in Part 1.

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Andrew Strikwerda January 12, 2017

In Part 2 of our blog series on multiscale modeling in high-frequency electromagnetics, we discuss a practical implementation of multiscale techniques in the COMSOL Multiphysics® software. We will simulate radiated fields using two different techniques and verify our results with theory. While these methods can be generally applied, we will always revolve around the practical issue of antenna-to-antenna communication. For a review of the theory and terms, you can refer to the first post in the series.

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Andrew Strikwerda January 11, 2017

This post begins a comprehensive blog series where we will look at several approaches to multiscale modeling in high-frequency electromagnetics. Today, we will introduce the supporting theory and definitions that we will need. In subsequent posts, you will learn how to implement multiscale modeling of high-frequency electromagnetics for different scenarios in the COMSOL Multiphysics® software. Let’s get started…

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Jiyoun Munn October 31, 2016

To keep our antenna modeling process efficient and accurate, we should start with a simple geometry and then gradually add more complex features. The final simulation needs to include enough detail to accurately represent our design, while excluding elements that needlessly increase the computational cost. To demonstrate this, we look at an anechoic chamber example, which is used to characterize antenna performance, before examining how this process applies to several antenna examples available in the COMSOL Multiphysics® software.

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Bridget Paulus August 8, 2016

Imagine a vehicle where you could simply plug in a destination and arrive without ever having to touch the steering wheel. Fully autonomous cars would revolutionize society, benefiting those who already drive and increasing the mobility of those who can’t. While technological advancements have brought us closer to such a reality, there are still many challenges to overcome. Today, we’ll explore the future of autonomous cars and what needs to happen before they can become a viable option.

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Jiyoun Munn July 4, 2016

When designing bandpass-filter type high-Q devices with the finite element method in the frequency domain, you will likely come across a situation where you need to apply many frequency samples to more accurately describe the passband. Simulation time is directly proportional to the number of frequencies included in the simulation of a microwave device, with the time increasing as the frequency resolution used becomes finer. Two powerful simulation methods in the RF Module help accelerate the modeling of such devices.

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