Bandwidth-Enhancement gm-C Filter with independent ¿o and Q Tuning Mechanisms in Both Topology and Control Loops

This paper deals with the proposal of a new topology for a gm-C continuous time filter which allows the adjustment and tuning of its characteristic parameters (ωO and Q) in an independent way (without cross-tuning), thereby extending the Q range of the filter for a particular ωO value. Additionally a comparison of three different Q-tuning algorithms is presented. It is shown that an LMS-based Q-control strategy allows to overcome the intrinsic dependence between the Q and ωO tuning loops. The combination of both the proposed filter topology and the selected control loop algorithms results in an enhanced transient performance as well as an improvement in terms of cross-detuning.Postprint (published version

Bandwidth-Enhancement gm-C Filter with Independent wo and Q Tuning Mechanisms in Both Topology and Control Loops

This paper deals with the proposal of a new topology for a gm-C continuous time filter which allows the adjustment and tuning of its characteristic parameters (ωO and Q) in an independent way (without cross-tuning), thereby extending the Q range of the filter for a particular ωO value. Additionally a comparison of three different Q-tuning algorithms is presented. It is shown that an LMS-based Q-control strategy allows to overcome the intrinsic dependence between the Q and ωO tuning loops. The combination of both the proposed filter topology and the selected control loop algorithms results in an enhanced transient performance as well as an improvement in terms of cross-detuning.Postprint (published version

Filtro gm-C para aplicaciones de comunicaciones con sintonía adaptativa del factor de calidad Q independiente de la sintonía de la frecuencia central

Este artículo muestra la propuesta de un filtro gm-C de segundo orden con control independiente total de la frecuencia central y el factor de calidad diseñado para aplicaciones inalámbricas multiestándar. Se presenta asimismo el diseño de los lazos de control adecuados para hacer la correcta sintonía del filtro tras una breve descripción de las ventajas e inconvenientes de las propuestas encontradas en la bibliografía. El trabajo se completa con una propuesta de mejora del lazo de control del factor de calidad que permite aumentar la rapidez del lazo y disminuir el error de rizado de la señal de control.Postprint (published version