RF Signal Transformation Between the Time and Frequency Domains

Jiyoun Munn September 25, 2018

When we analyze high-frequency electromagnetics problems using the finite element method (FEM), we often compute S-parameters in the frequency domain without reviewing the results in the complementary domain; that is, the time domain. The time domain is where we can find other useful information, such as time-domain reflectometry (TDR). In this blog post, we will demonstrate data conversion between two domains in order to efficiently obtain results in the desired computation domain through a fast Fourier transform (FFT) process.

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Jiyoun Munn April 3, 2018

Since high-speed communication is inevitable for evolving wireless systems, the demand for a higher data rate, higher frequency, larger spectrum, and wider bandwidth increases. When dealing with a wide bandwidth, multiple devices may have to be deployed in a wireless communication system to filter out unwanted noise and interfering signals, enhance the signal-to-noise ratio, and improve the sensitivity. A single tunable filter can replace these devices, reducing the system’s size and weight and the fabrication cost of multiple components.

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Jiyoun Munn July 19, 2017

When simulating electromagnetic devices, a common mistake is putting everything into a model at the same time, including a complicated geometry, complex material properties, and a mixed bag of boundary conditions. This makes the model run for a long time and you might get frustrated when your simulation results are physically wrong, without any clues as to why. Today, we will discuss how to efficiently set up simple RF, microwave, and millimeter-wave circuit models in the COMSOL Multiphysics® software.

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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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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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Jiyoun Munn June 1, 2016

The 5G mobile network and Internet of Things (IoT) are two hot topics in the RF and microwave industry. New developments in these wireless applications call for much higher data rates, active electronically scanned arrays (AESA), phased array antennas, and multiple-input-multiple-output (MIMO) technology. It is important to reduce the time and cost during the process of prototyping and manufacturing these applications. Using simulation and apps, we can streamline the development cycle of wireless communication designs.

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Jiyoun Munn July 1, 2015

In electromagnetics simulations, the ultimate goal is to boost the efficiency and productivity of your device by closely mimicking the effects observed in reality. This process requires an understanding of the reality you are trying to describe and mimic, as well as the details that should be included. Let’s explore the reality of electromagnetic waves with regards to the measurement environment.

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Jiyoun Munn May 4, 2015

What if you could enable non-experts to run your multiphysics simulations on their own? You would save time, for sure, and they would get easy access to your expertise. Turning your simulations into apps with customized and easy-to-use interfaces is now a reality. Here, I will explain why you should start creating apps and how to go about it. We’ll use the new Corrugated Circular Horn Antenna Simulator demo app to guide us.

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