Editor's Note: Better measurements improve models

Ever since companies began getting serious about EMC, engineers have treated it as an assembly-level or system-level phenomenon. This made sense because the electromagnetic energy emitted by a system is highly dependent on its configuration.

The problem with this approach is that you must wait until you have prototypes to test for EMC compliance, and if design changes are needed, they can be difficult and expensive. To catch potential problems, manufacturers have begun to model the EMC performance of their designs before they build prototypes. By doing so, they can find potential problems before they choose components and lay out PCBs.

The effectiveness of these simulations depends heavily on the accuracy of the component models used to perform them. If the models don't accurately predict the RF energy emitted by an IC, then there's no way that the simulation will produce usable results.

Better models will produce better results, and the way to produce better models is to make better measurements. This is why the IEC is working so hard on developing standard methods for measuring the radiated emissions and EMC immunity of ICs. (See article on p. E5.)

While these test methods are still works in progress, they are a strong step forward. Accurate measurements will enable IC makers to improve the performance of chips and help system designers to more easily comply with EMC standards.

Contact Dan Romanchik at editor@aatr.net.