620 BELL SYSTEM TECHNICAL JOURNAL 



as in the present case of a composite wave-filter. Simple relations 

 exist here between these parameters of the transducer and of its parts, 

 as shown in the text, which is not true with the other parameters. 

 The recurrent parameter formulae, on the other hand, apply more 

 naturally when dealing with a succession of identical dissymmetrical 

 sections, or of different dissymmetrical sections whose characteristic 

 impedances in one direction are equivalent, in which cases the propa- 

 gation constant of the transducer is equal to the sum of the progaga- 

 tion constants of the parts. In conclusion, it is seen that the set of 

 parameters most suitable for use in any case depends upon the par- 

 ticular structure of the transducer. 



