Analogue VLSI-applications of the technique

Probably the earliest area in which analogue VLSI gained hold was in radio receivers. Work on radiopaging receivers using direct conversion techniques has led to the acceptance by the marketplace of this approach, while recent developments in the field of logarithmic amplifiers has seen performances produced that would have been considered impossible in a production environment ten years ago. However, in many cases, before the integration can take place, serious consideration has to be given to the optimisation of the system architecture, as the classical architectures are not always practically suited to integration. For example, the superheterodyne receiver in its classic form has distributed selectivity, and integration requires currently the substitution of block filtering. It is interesting to note however, that some work has been reported on active on-chip filters which would allow the tuned circuits of the superhet of be reproduced in a totally integrated form