Lumped Elements

This page serves as the main page for our discussion on capacitors, resistors and inductors at microwave frequencies.

Click here to go to our lumped element filter page

Click here to check out a lumped element Wilkinson design

Click here to check out a video of another lumped element Wilkinson design by Sebastian (new for January 2022)

Click here to check out a lumped branch-line coupler design

Click here to check out a bias tee design using lumped elements

Click here for a discussion of how to calculate inductance and capacitance of transmission lines

What is a self-resonant frequency and how do you model it? It is all explained here

Here's a video from Keysight on modeling lumped elements. With increasing operating frequencies, the modeling of passive components becomes increasingly important, and aren't any ready-to-use models for inductors, resistors, capacitors etc. This video explains and demonstrates a method to develop accurate Spice models from verified S-parameter measurements. By using an easy to follow, step by step procedure, this video walks you through the entire modeling flow for an on-wafer capacitor, using the Keysight Measurement and Modeling Software IC-CAP.

The IC-CAP project can be downloaded, together with a detailed How-to-Use description and an in-depth tutorial about passive components modeling, applying the demonstrated method.

Franz Sischka explains lumped element modeling

What is a lumped element? it is defined here at Microwaves101 as a passive device, that is reciprocal (these definitions are on our network theory page). But just as important, it must follow this rule of thumb!

Lumped Elements To be considered a "lumped element", no feature of its structure can exceed 1/10 of a wavelength at the maximum frequency of its usage.

That being said, of the three primary lumped elements, resistors are the most well behaved as microwave elements, followed by capacitors, then inductors. It is possible to make lumped resistors and capacitors that work up to 100 GHz, but inductors usually stop being useful at X-band or lower.

Lumped elements don't always come in arbitrary values. Check out our page on RETMA values.

More to come!



Author : Unknown Editor