Ardem Associates (San Dimas, CA) announced that Dr. R. David Middlebrook, Professor Emeritus of Electrical Engineering at California Institute of Technology, has introduced his new "General Feedback Theorem (GFT): A Final Solution for Design-Oriented Feedback Analysis," which identifies the correct loop gain even in the presence of inevitable nonidealities. It is presented on CD and contains a three-hour, live, first-time presentation by Dr. Middlebrook.
The General Feedback Theorem is the culmination of Dr. Middlebrook's efforts to develop a framework for expressing the important features of a feedback system, such as loop gain, directly in terms of recognizable physical paths in the circuit model. The conventional "bottom-up" approach attempts to identify distinct blocks from the circuit model, which usually involves guesswork and approximation because the blocks are not really separable. In contrast, the GFT is a "top-down" approach in which a natural block diagram is part of the answer.
The Intusoft ICAP/4 GFT templates control all the simulations and separately identify the non-idealities. To access the GFT for design simulation, Intusoft has implemented the GFT into its downloadable ICAP/4 demo CD, located at http://www.intusoft.com/cgi/regnow.exe?for=demos.htm. In addition to this complete toolset for schematic entry, SPICE simulation and design verification, the product includes GFT templates. The templates calculate all the GFT constituent transfer functions generated by a user-specified, test signal injection configuration.
