High-frequency technology didn’t earn its reputation as black magic for no reason. Unlike low-frequency circuits, microwave circuits don’t behave in a totally predictable way, so “tweaking” has been an accepted mainstay of the microwave design approach/fl ow. Fortunately, high-frequency design tools have dramatically improved so that tweaking of prototype circuits is much less common, and today’s engineer has powerful tools that can make sense of the black magic.

As this white paper will demonstrate, AWR’s Visual System Simulator (VSS) design environment, a comprehensive software suite for design and optimization of communications systems, provides insight early in the design process about how a circuit, subsystem, or system will perform, enabling designers to make changes up front in component values and circuit confi gurations with far less effort. It doesn’t matter whether the ultimate application is a wireless base station or mobile device, radar system, or surveillance receiver, VSS can iron out potential diffi culties—before they become show stoppers.

System-level Analysis

VSS is a natural evolution of the way most designers accomplish system-level analysis: by using offi ce productivity software such as Microsoft Excel (Figure 1). VSS accounts for the most important factors—component mismatches and phase noise—that affect system performance. It also allows circuit designs or S-parameter fi les to be imported into them, offers a library of components from which to choose, can pinpoint the source of a spurious response or intermodulation product, and much more.