Reconfiguration of cascade /spl Sigma//spl Delta/ modulators for multistandard GSM/Bluetooth/UMTS/WLAN transceivers

This paper presents design considerations for cascade sigma-delta modulators (SAMs) included in multistandard wireless transceivers. Four different standards are covered: GSM, Bluetooth, UMTS and WLAN. A top-down design methodology is proposed to find out the optimum modulator architecture in terms of circuit complexity and reconfiguration parameters. The selected 2-1^L-2 expandible SigmaDeltaM is high-level sized and several reconfiguration strategies are adopted at both architecture- and circuit-level in order to adapt the modulator performance to the different standards requirements with adaptive power consumption. Time-domain simulations are shown to validate the presented approach