WAVE FILTERS 71 



The impedance of the series arm in the three systems is 



zei = j(JiL 4.60 



Zmi = jo^m 4.61 



zai = joiM 4.62 



The impedance of the shunt arm in the three systems is 



1 



Ze2 



JcoCe 



1 



4.63 

 4.64 

 4.65 



22 22 



~J~Ce ~pce ~P<:e: 



c. M c. M c. 



ELECTRICAL MECHANICAL ACOUSTICAL 



Fig. 4.9. Low pass wave filters. (Courtesy of The Blakiston Company from Olson and 



Massa, " Applied Acoustics.") 



From the constants of the systems, 



— = — LCe<^? = 0, when Wc = 4.66 



Z2E 



— = ^— jiiCmo^c^ = 0, when coc = 4.67 



Z2M 



— = - MCmcoJ" = 0, when coc = . 4.68 



22A 



ZlE 2 



— = — LCeojc^ = — 4, whencoc = , 4.69 



Z^E 'S/LCe 



— = — mCM^c = — 4, when coc = , 4.70 

 Z2M -s/mCM 



— = — MCaWc" = — 4, when Wc = , 4.71 



284 y MCa 



