Wave realisation of filters and equalisers in log-domain

Log-domain circuits offer a low-power property, whereas wave-derived circuits inherit a low-sensitivity property from the ladder prototypes and are less prone to transistor non-idealities. A novel approach to the design of wave filters in the log-domain is presented and several wave two-port topologies are investigated. Important design properties are examined. Realisations of direct filters, complex filters and group-delay equalisers in typical BJT and HBT SiGe BiCMOS technologies are assessed. The design procedures have been incorporated into XFTLTER design software.