The traditional approach to RF/microwave circuit design — the basis of today's high-frequency wireless designs — is being pressured simultaneously by an increase in operating frequencies and bandwidth and a decrease in physical footprint size. The result is that the physical design challenges faced by circuit designers are rapidly increasing, while choices for how these challenges should be best addressed are not.

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The drive to put more functionality into the same or smaller space is particularly demanding on the RF/microwave design flow because of the increased and unavoidable need to model interconnects and their interactions. Ideally, modeling all of the interactions at the schematic level, using distributed line, discontinuity, and coupled-line models is preferred. While there is nothing preventing an engineer from doing this, the complexity of modern wireless designs makes this an unrealistic and unreasonable approach, given that this manual process is incredibly time consuming and error prone.

Consequently, the engineer's response has been to forego design and go straight to analysis/verification as a weak, but faster, alternative. While this method saves engineering time by avoiding the manual insertion of various RF/microwave line models, the trade-off is that the overall engineering time grows as the analysis/verification burden for using EM as a design tool has mushroomed.

The reality has unfortunately become infinite layout-EM-analysis cycles as lines are moved and vias replaced. This is all being done without any design engineering methodology, first-principles insight, or parametric handle into or behind the reasons for doing so. This situation is all the more critical when considering that by the time a layout is complete enough to do this sort of layout-EM-analysis cycle, the design is closer to the end of its cycle than the beginning. Study after study on the engineering of complex systems, from spacecraft to software to electronics, shows that it is much more cost-effective to identify and fix design deficiencies as early as possible in the design cycle. However, doesn't this mean that the improper use of EM as a design tool makes this a costly and risky proposition to many RF/microwave design flows?

EDA developers are working to “catch up” with the multitude of design challenges created by the exploding wireless communications market. This article describes the new ACE technology and discusses real-world design examples where the new software provides an accurate, efficient, modern methodology as an alternative to traditional RF/microwave design approaches that no longer meet the challenges of next-generation communications product design.

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