Computation Methods for Broad-Band 90° Phase-Difference Networks

The pole-zero frequencies and phase deviations of four-, six-, and eight-pole broad-band 90° phase-difference networks are derived by algebraic means. The results agree with those obtained by elliptic functions but lead to simpler computer solutions. An design method based on a bridge circuit is developed. The conditions for minimum loss, maximum stability, and minimum number of circuit elements are stated for unterminated and terminated network pairs. Computer methods for obtaining network component values and circuit characteristics are described. A timesharing computer program is available for four-, six-, and eightpole networks and all frequency ranges.