Structural controllability and reducibility of RLC networks with bipolar transistor

If the values of all elements in RLC network with BJT (bipolar junction transistor) are regarded as independently variable parameters, the network is defined over the field F(z) of all rational functions in its physical parameters. Some concepts and results on reducibility and separability are presented; the structural controllability problems for this network are discussed. A simple way to conclude structural controllability for a RLC network with BJT is obtained.