Continuous-time Sigma-Delta Modulators for Highly Digitised Receivers

This paper presents an overview of recent developments in continuous-time sigma-delta modulator design. Traditionally, sigma-delta modulators have been used for audio applications with low bandwidth and high-resolution requirements. Nowadays, the area of sigma-delta modulation has extended and sigma-delta modulators are widely used in multi-mode communication receivers with different bandwidth and resolution specifications. Thanks to new architectures and the integration of extra functionality, the excellent power efficiency, as well as good scalability, continuous-time sigma-delta modulators are key in enabling highly digitized receivers.