Analog to digital conversion: technical aspects

An ideal radio communication receiver places the analog to digital conversion just after the antenna. It is an objective in a Òsoftware radioÓ perspective. The available silicon technologies do not provide the performance required by this application. We are able to evaluate the present limits and the gap between these limits and the ideal solution proposed. In this paper, we describe the present possibilities in terms of receiver architectures and we deduce the ADC speciÞcations. Then we analyse different ADC architectures adapted to this application. The choice is mainly between pipeline and sigma-delta ADC. We compare them in terms of power consumption and we introduce a factor of merit. The future technologies will have an impact on ADC performance. Superconductor technology applied to ADC may be a solution and it is analysed at the end of this paper. Þn de cet article.