Topic summary
Ladder network
Extracted from the Wikipedia article Electronic filter topology.
Ladder topologies
A ladder network consists of cascaded asymmetrical L-sections (unbalanced) or C-sections (balanced). In low pass form the topology would consist of series inductors and shunt capacitors. Other bandforms would have an equally simple topology transformed from the lowpass topology. The transformed network will have shunt admittances that are dual networks of the series impedances if they were duals in the starting network - which is the case with series inductors and shunt capacitors. Ladder filters were often implemented with crystal resonators for steeper transition.