DISTORTIOX IN NOISE MODULATED FM SIGNAL 889 



tabulated in Table 4.2 of Reference 4 and 



a = 27rfT, U = 2wfbT. (5.12) 



The parameters a and k that appear in the table are defined by 



a = f/fb and /,• = 8/5T. 



These formulas serve to supplement the formulas and curves given by 

 Medhurst and Small. 



ACKNOWLEDMENT 



I wish to express my thanks to H. E. Curtis who has furnished some 

 of the examples given in this paper and to E. D. Sunde, S. Doha, and 

 others for their helpful comments. 



REFERENCES 



1. J. R. Carson and T. C. Fr}^ Variable Frequency Electric Circuit Theory With 



Application to the Theory of Frequency Modulation, B. S.T.J. , 16, 5l0-540, 

 Oct., 1937. 



2. B. van der Pol, The Fundamental Principles of Frequency Modulation, Jl. 



I.E.E., 93, pp. 153-158, 1946. 



3. R. G. Medhurst and G. F. Small, Distortion in Frequency-Modulation Systems 



Due to Small Sinusoidal Variations of Transmission Characteristics, Proc. 

 I.R.E., 44, pp. 1608-1612, Nov., 1956. 



4 . W. R. Bennett, H. E. Curtis, and S. O. Rice, Interchannel Interference in FM 

 and PM Systems Under Noise Loading Conditions, B.S.T.J., 34, pp. 601-636, 

 May, 1955. The same problem has been treated independently and in much 

 the same way by S. V. Borodich, On the Nonlinear Distortions Caused by 

 Variations of the Antenna Feeder in Multichannel Frequency Modulation 

 Systems, Radiotekhnika, Moscow, 10, pp. 3-14, 1955. 



5. These results are closely associated with some given bv M. K. Zinn, Transient 

 Response of an FM Receiver, B.S.T.J., 29, pp. 714-731, 1948. 



