In the analog circuit synthesis and optimization area, a trend
toward easily extensible open analog design systems has been
evident. Compared to initial knowledge-based approaches, the big
advantages of the more recent optimization-based approaches
are their high flexibility and extendability, both in terms of
design objectives and in terms of the ease of adding new circuit
schematics. More research is needed, but much has been achieved
in the past ten years with experimental analog synthesis systems