Dear Dennis...

EN-Genius Network's Dennis Feucht answers your design queries in his new Circuit Design Clinic!

July, 2008

 Dear Dennis

EN-Genius Network presents a new, interactive analog design service to readers! Send us your design questions (with relevant data; schematics in JPEG or GIF, please) for some free engineering advice from EN-Genius Network's circuit consultant, Dennis Feucht, on how you might solve a design problem or improve circuit performance. Submissions may be edited for clarity or brevity, and submitters and their email addresses will remain anonymous (unless otherwise indicated). Please send your questions to Dennis here.


Design Techniques For New Engineers:
The Complex-Frequency or s Domain
by Dennis L Feucht

One of the first circuits courses in electrical engineering is passive circuits (or networks). In this course, the Laplace transform is introduced, often to be reintroduced by the math department in the second term of differential equations. The key variable of the transform is s, the complex frequency. The transform converts equations in time, t, to equations in s. Because both t and s are the independent variables, they are defined over the domain of the function while the dependent variable, f(t) or F(s), has a defined range. This is basic function terminology which leads to engineering talk about the “time domain” and “frequency domain.”

...download complete article here (322 KB PDF)

Send this page to a Colleague!

Return to the designDEN