This paper deals with general discussion over high speed data converter architectures. Nowadays, more and more researches are focused on the ability to design transceivers able to manage digital data as soon as possible right behind the antenna. These so-called Software Defined Radio architectures are one of the easiest ways to design a receiver with low time-to-market impact. Furthermore, most of the recent standards impose either very high frequency ranges, large bandwidth signals and numerous number of bits. Indeed, different topologies of analog-to-digital and digital-to-analog converters are discussed, keeping in mind the very high frequency purpose. To conclude this paper, two designs are presented: a wideband 3-bit 4Gsps Flash converter and a narrowband 12-bit 4Gsps Continuous-Time Delta-Sigma converter.