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Article: Boldly going beyond S-parameters.(SIGNAL ANALYZERS)
- Article from:
- EE-Evaluation Engineering
- Article date:
- April 1, 2009
- Author:
CopyrightCOPYRIGHT 2009 Nelson Publishing. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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It's not for nothing that RF and microwave design have long been considered close to black magic. As in many areas of expertise, a few fundamental principles apply, but a great deal of engineering experience and judgment has been required to achieve results close to those that theory predicted.
Today, thanks to powerful circuit simulation software and good device models, an engineer can easily design a small-signal RF amplifier. Scattering or S-parameters completely describe the linear behavior of semiconductor devices. Unfortunately, power amplifiers operate outside the small-signal superposition assumptions underlying the use of S-parameters. The signal levels ...