Power Control by Telephone
Introduction To Modern Network Synthesis Van Valkenburg.pdf [patched]
**Note
Van Valkenburg doesn't just present the formulas; he derives the pole locations in the complex s-plane, allowing students to visualize why these filters behave the way they do. Introduction To Modern Network Synthesis Van Valkenburg.pdf
If ( Z(s) ) has a pair of imaginary-axis poles at ( s = \pm j\omega_0 ), then: [ Z(s) = \frac2k ss^2 + \omega_0^2 + Z_2(s) ] where the first term represents a parallel LC tank with ( L = \frac12k ) and ( C = \frac2k\omega_0^2 ), and ( Z_2(s) ) is of lower degree and still positive real. **Note Van Valkenburg doesn't just present the formulas;
"When testing if a function is positive real, always check: (1) ( Z(s) ) is real for real ( s ), (2) ( \operatornameRe[Z(j\omega)] \ge 0 ) for all ( \omega ), and (3) poles and zeros in the right-half plane are simple with positive real residues." Introduction To Modern Network Synthesis Van Valkenburg.pdf