and modeling technique for a wide variety of systems. Properly extended, it is applica- ble to virtually every system whose behavior is characterized by the presence of widely spaced time constants. Moreover, it is not required for these systems to be autonomous. In [Vana02e], the theory was extended to handle, for instance, PLL large-signal behav- Finally, it would be interesting to explore the link with the HTM framework discussed in the previous chapters. Projection of the perturbation terms requires us to solve sys- tems of linear DAEs. In many cases, these systems turn out to be periodically time- varying. Hence, they can be solved using HTM-based techniques. A practical ap- plication is, for instance, the computation of the ISFs that are required for oscillator phase-noise computations. Chapter 6 Conclusions That's all folks! -Woody Woodpecker his book has presented theory, methods and algorithms to support efficient and systematic modeling and analysis of telecommunication frontends and their build- ing blocks. Focus was given to linear periodically time-varying (LPTV) systems and autonomous systems (oscillators). The resulting methods apply to a wide variety of systems and problems: the characterization of signal transfers in mixers, a PLL's time- varying stability behavior, noise folding in PLLs, oscillator injection-locking behav- ior, oscillator phase noise behavior, etc. Moreover, the development of all theory and methods was accompanied by the development of a sound intuitive understanding of the system behavior being studied: the story behind the math was considered as im- portant as the math itself. As such, this work contributes to a better understanding of the behavior of telecom frontend building blocks and to the mathematical techniques necessary for systematic analysis of such systems. 6.1 Main achievements The work presented in this book contributes to the state-of-the art in the analysis and modeling of telecommunication frontends and their building blocks. The two main subjects that it has 