7()() THE BELL SYSTEM TECHNICAL JOURNAL, AL\Y 1954 



The coefficients ai , a2 •••««•• • are determined in the usual manner 

 by Fourier series analysis to represent the function 





(8.02) 

 over the frequency band. If Aoiu) closely approaches A(co) the fine 



-0>^ 2 



\ 



\ 



(a) RATIO /\{CO)//\q{CJ) 



NUMERALS ON CURVES CORRESPOND TO 

 THOSE ON IMPULSE CHARACTERISTICS BELOW 



CO, 



FREQUENCY 



2U}, 



Fig. 29 — Effect of slow cosine variation in amplitude characteristic when 

 amplitude at zero frequency is held constant. 



