26 



BELL SYSTEM TECHNICAL JOURNAL 



Fig. 1 — Spherical coordinates. The positive directions of r-, 9-, and (^-components 

 of a vector are, respectively, the directions of increasing r, 6, and <p. 



and the impedance in the direction of increasing <p are : 

 Ze = 



H^ Hr ' 



7 — ^ — — ^ 

 "'He' Wr 



In cylindrical coordinates we have (Fig. 2) : 



Z =-^ 



//!' 



y -C/2 zip 



F F 



Fig. 2 — Cylindrical coordinates. The positive directions of p-, <p-, and z-coniponents 

 of a vector are, respectively, the directions of increasing p, tp, and z. 



