WAVE FILTERS 



73 



ZiA 

 Z2A 

 ZiE 

 Z2E 

 ZlM 

 Z2M 

 ZlA 

 ZoA 



1 



MC4CO, 

 1 



- = 0, when coc = 



1__ 



1 



MC 



AOOc" 



; = — 4, when coc = 

 = — 4, when coc = 

 = — 4, when coc = 



1 



WlCe 

 1 



1-\/ mCu 

 1 



2VmC^ 



4.80 



4.81 



4.82 



4.83 



Equations 4.78, 4.79, 4.80, 4.81, 4.82 and 4.83 show the systems of 

 Fig. 4.10 are high pass wave filters transmitting currents, velocities or 

 Volume currents of all frequencies lying between the cutoff frequency fc 

 where /c = (Jic/li^, and infinity. 



F. Band Pass Wave Filters. — Electrical, mechanical and acoustical 

 band pass wave filters are shown in Fig. 4.11. 



ra=nCH 



ELECTRICAL MECHANICAL ACOUSTICAL 



Fig. 4.11. Band pass wave filters. 



The impedance of the series arm in the three systems is 



ze\ = jo^Li 



Zmi = jo^mi 



zai = ji^Mi 

 The impedance of the shunt arm in the three systems is 



ZE2 ^ ' 



1 — oi^CsLi 

 jw7n2 



Zm2 



ZA2 = 



1 — (jrCu'tn^ 



jwM2 



1 - co^C^Mz 



4.84 

 4.85 

 4.86 



4.87 

 4.88 

 4.89 



