The second generation current conveyor (CCII) is an adaptable multifunction component that can be applied in a large number of analog circuits (such as active continuous time filters and all-pass networks
) and has been the subject of intensive study for the last decade [1-4].
Lin, "High output impedance current-mode first-order all-pass networks
with four grounded components and two CCIIs," International Journal of Electronics, vol.
A quadrature filter using active all-pass networks
is an attractive solution since the filter poles can be adjusted independently and each adjustment requires a change in only one component.
It is important that all four blocks be designed completely symmetrical except for two variable GaAs MESFETs used as variable resistors in the two all-pass networks
of the quadrature power splitter.