Topology Issues

• Classical WDFs are composed of parallel and series connections of elements

• A Binary Connection Tree (BCT) can represent any such parallel/series network

• $R$ -Nodes
  • Some circuits, such as the ``bridged T'' circuit, cannot be represented using parallel/series connections of elements
  • These circuits are modeled using more general scattering matrices (Belevitch)
  • Such circuits are called $R$ -Nodes in the overall WDF network graph
  • $R$ -Nodes connect naturally to BCT graphs, since all signals are compatible traveling-wave components
  • An open issue is how to minimize the computational complexity of $R$ -node scattering matrices