High Frequency Communication and Sensing

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Lumped vs. Distributed Elements

Lumped circuit models, such as resistors, capacitors, and inductors, are used to evaluate the response of a circuit relative to low frequency. At sufficiently high frequencies, the lumped model of an element is no longer an accurate representation of its behavior. More specifically, this occurs when the operation frequency is comparable with the traveling speed of the voltage and current waves across the element boundaries. In other words, when the wavelength of the traveling wave becomes comparable with the element dimensions, we can no longer assume that the voltage or current waveforms are constant across the element dimension. In this case, we must consider modeling the element using distributed circuit ...