Sigma-Delta Converters: Practical Design Guide, 2nd Edition

10 Frontiers, Trends and Challenges: Towards Next‐generation Modulators

Since the invention of modulation techniques, a multitude of ICs has been developed, using diverse technology processes and architectural and circuit techniques, and targeting a huge number of applications – ranging from high‐resolution A/D interfaces for sensors and instrumentation to ultra‐low‐power biomedical applications and broadband communications [[1]–[4]]. However, the original concepts and fundamental signal processing techniques behind Ms have evolved a lot in recent years. Moreover, new application scenarios require innovative solutions to meet increasingly demanding specifications in a power‐efficient manner, thus leading to a new generation of converters. An example is RF digitizers for SDR‐based receivers, in which part of the RF signal processing is embedded in the loop [[5]]. Others examples use digitally‐assisted analog circuits in the loop filter [[6], [7]] or time‐to‐digital conversion ...