Lumped elements

Updated June 29, 2007

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

Lumpy, the lumped element mascot

Click here to go to our lumped element filter page

Click here to check out a lumped element Wilkinson design (new for March 2007!)

Click here to check out a lumped branchline coupler design

Click here for a discussion of how to calculate inductance and capacitance of transmission lines (new for February 2007!)

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!

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.

More to come!