Basics of Response Feature Technology

The major challenges of simulation-driven design include a high computational cost associated with massive EM simulations of the system at hand. Consequently, the majority of the conventional optimization and modeling procedures as well as statistical design methods cannot be directly applied to handle full-wave models. Surrogate-assisted techniques can be employed to mitigate these problems to a certain extent. Notwithstanding, a typically high nonlinearity of frequency characteristics of antennas and microwave components creates additional problems, e.g., the necessity of using global optimization strategies for parameter tuning or insufficiency of standard modeling methods when constructing fast replacement models. The response feature technology, the main topic of this book, offers some unique alternatives when it comes to handling EM-driven design tasks. The benefits of this technology come in different forms, either by expediting the optimization procedures, by simplifying the problem at hand, or by regularizing the functional landscape to be handled by numerical algorithms. This chapter gives the first exposition of the response feature approach. More specifically, it introduces the concept of characteristic points, discusses their properties, and demonstrates the benefits of applying them for design purposes, here, local gradient-based parameter tuning. The remaining parts of the book will cover utilization of response features in different contexts, including accelerated local and global search, multi-objective design, as well as low-cost statistical analysis and surrogate model rendition.