The Air Force

ion. Different levels of system modeling abstraction usually involve different techniques for model representation and solution. A continuous-time dynamical system might be represented by a set of coupled differential equations. Traditional system-level tools solve the differential equations by approximation with finitedifferences. Circuit-level tools like SPICE (Simulation Program with Integrated Circuit Emphasis) solve the differential equations with an iterative solution technique that is more accurate, but more time consuming. An environment is needed which can support a mixture of representation and solution techniques. Techniques to be considered for this effort would include discrete-event simulation, continuous-time simulation, and RF and circuitlevel simulation. A focus of the effort will be the integration of the various modeling techniques. A useful modeling and simulation tool should use graphical techniques for problem setup and results analysis to the extent possible. Novel graphical techniques or combinations of graphical techniques will be explored. The use of system description languages such as A-VHDL (Analog VHSIC Hardware Description Language), MHDL (Microwave Hardware Description Language), or SPICE related models would be desirable. PHASE I: 1) Develop detailed design/documentation for a multi-level modeling and simulation capability. 2) A simple prototype of the combination of modeling/simulation techniques shall be demonstrated as proof of concept for Phase II development. 3) The Phase I effort shall result in a detailed plan for Phase II. PHASE II: Develop a full working prototype of the multilevel modeling/simulation capability. The Phase II effort will result in a system that is ready for full-scale commercial development. PHASE III DUAL USE APPLICATIONS: Development of a multilevel modeling and simulation capability would benefit all electronic systems development, whether for commercial or military use. Telecommunications and satellite systems are just a few examples of areas where both commercial and military systems would benefit from an enhanced modeling and simulation capability. REFERENCES: Simulation of Communication Systems, Jeruchim, Balaban and Shanmugan, 1992, Plenum Press, New York. AF98-080 TITLE: Very High Efficiency DC-DC Converter