The design of broad-band active delay line/90° phase difference networks

The general configuration of a delay line/90° phase difference network having a single input and two outputs is defined. The group delay from the input to each output is specified over a frequency range as well as the phase difference between the two outputs. A procedure is outlined for obtaining the singularities associated with this type of configuration. The general procedure for realizing active networks corresponding to the singularities is discussed. The actual active network realizations are obtained in a form that is easily implemented as a thickfilm hybrid circuit.