Most high-frequency designers will admit to help from the latest computer-aided-engineering (CAE) software tools, perhaps relying on a traditional circuit simulator or even exploring the coupling possibilities of a stripline or microstrip circuit using an electromagnetic simulator. After all, the excellent performance achieved with the ZX30-20-462HP+ bidirectional coupler from Mini-Circuits (see story below) owes some credit to the design tools found in the Advanced Design System (ADS) software suite from Agilent Technologies.
Still, few designers may admit to enlisting one CAE tool to check another. This growing trend of co-simulation, makes the best of multiple simulation tools to achieve higher levels of accuracy than possible by using a single tool. The co-simulation approach, which was impractical prior to the availability of multiple-core-processor computers, gives designers an extra edge when evaluating a design, for example, on different dielectric materials or with different widths of transmission lines. It is a feature that is increasingly available as part of multifunction simulation suites, such as the ADS suite from Agilent and Microwave Office from Applied Wave Research. In some cases, two simulators may be better than one.