Notes on bridged-T complex conjugate compensation and 4-terminal network loading

MANY servo systems possess open-loop transfer functions which contain one or more pairs of complex conjugate poles. Often a pair of these complex conjugate poles will lie close to the imaginary axis and will cause the uncompensated system to possess a relatively poor damping ratio or damping exponent. Usually, satisfactory compensation of such systems can be achieved through the use of tachometer feedback or the conventional compensators possessing real axis singularities. However, there are occasions when complex conjugate singularity compensation would possess distinct advantages. This is particularly true if the compensating complex singularities can be introduced by a simple R-C (resistance-capacitance) passive network with zero d-c attenuation.