.+90, 



Phase 



High-pass 

 r filters 



shift 



I Low- pass 

 ^ filters 



OVCR' 



0\/CR' 



\/CR 

 iju increasing 



WCR' 



100/Cff 



Graph 13. Phase characteristic of limited phase shift filters 



lOO/Cff 



Graph 14. Transmission characteristic of R-C band-pass filter 



269 



