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An accurate, continuous-time, active IC filter based on G[sub m]-C integrators dedicated to the design of high dynamic range, low-oversampling ratio (OSR) continuous-time (CT) sigma-delta (ΣΔ) modulators is presented. Despite temperature and process variations, the biasing technique used enables design of a constant G[sub m]-C cell without additional tuning circuit. A zero-IF (ZIF) receiver has been designed integrating I (in-phase) and Q (quadrature-phase) ΣΔ modulators. The measured peak SNR for a single modulator is 82.5 dB in temperature range [-30°C, +85°C]. Its power consumption, including I and Q modulators, biasing circuitry and delay-locked loop is 7.25 mW under 2.5 V. [ABSTRACT FROM AUTHOR]

A full-wave analysis extending the transverse resonance technique to inhomogeneous stacks is considered to investigate coupling effects in typical BiCMOS structures. Dependences of crosstalk on the presence of buried epitaxial layers (BEL), the line spacing and the substrate thickness are presented. The use of low-resistivity localised diffusions to interrupt BEL yields significant isolation improvement. [ABSTRACT FROM AUTHOR]