Narrow-band variable center frequency single-loop and multistage sigma-delta modulators for bandpass signals

Oversampled narrow-band single-loop and multistage resonator-based bandpass sigma-delta (Σ-Δ) modulators that can accommodate different passband center to sampling frequency ratios are reported. These tunable bandpass configurations are designed by analytically determining and subsequently verifying through detailed empirical simulations the required compensation hardware to deliver enhanced noise-shaping. It is demonstrated that comparatively superior in-band signal-to-noise ratios and dynamic ranges are attributed to the inclusion of appropriate digital feedforward and feedback compensators within these structures.

Tunable centre frequency resonator based bandpass Σ-Δ modulators

This paper presents a methodology for the design of oversampled narrow-band single-loop and multi-stage resonator-based bandpass Σ-Δ modulators that can accommodate different passband centre to sampling frequency ratios. These tunable bandpass configurations are designed by analytically determining the required compensation hardware to deliver good resolution. Thorough simulations demonstrate that comparatively superior in-band signal-to-noise ratios (SNRs) and dynamic ranges (DRs) are attributed to the inclusion of appropriate feedforward and feedback compensators within these structures.

Critical autopoiesis and the materiality of law

Autopoietic theory is increasingly seen as a candidate for a radical theory of law, both in relation to its theoretical credentials and its relevance in terms of new and emerging forms of law. An aspect of the theory that has remained less developed, however, is its material side, and more concretely the theory’s accommodation of bodies, space, objects and their claim to legal agency. The present article reads Luhmann’s theory of autopoietic systems in a radical and material manner, linking it on the one hand to current post-structural theorisations of law and society, and on the other hand extending its ambit to accommodate the influx of material considerations that have been working their way through various other disciplines. The latter comprises both a materialisation of the theory itself and ways of conceptualising the legal system as material through and through. This I do by further developing what I have called Critical Autopoiesis, namely an acentric, topological, post-ecological and posthuman understanding of Luhmann’s theory, that draws on Deleuzian thought, feminist theory, geography, non-representational theory, and new material and object-oriented ontologies. These are combined with some well-rehearsed autopoietic concepts, such as distinction, environment and boundaries; Luhmann’s earlier work on materiality continuum; more recent work on bodies and space; as well as his work on form and medium in relation to art. The article concludes with five suggestions for an understanding of what critical autopoietic materiality might mean for law.