IDEAL FILTERS 



233 



10 



10" 



(O 10 2 

 < 



I 



> 10 



z 



,-3 



0.1 



0.2 



0.3 



0.7 



08 



09 



10 



0.4 05 0.6 

 FREQUENCY 

 Fig. 5 — Low pass filters with a = 1/12. Envelopes of phase departures 



1.25 



1.50 



2.50 



2.75 



.75 2.00 2.25 



FREQUENCY 



Fig. 6 — Low pass filters with a. = 1/12. Attenuation. 



