Ch. 8] CONCLUSIONS 75 



of the phase characteristic, transient response, and the uniformity of the 

 gain — to say nothing of over-all circuit complexity. Therefore, it seems 

 clear that no general theory of noise performance of such wideband 

 systems should be undertaken without attention to other system require- 

 ments. 



The last point brings us to the question of the usefulness of an optimum 

 noise-performance criterion of the type we have presented in this study. 

 It is probable that such a criterion will serve primarily as an indication of 

 the extent to which a given design, which has met a variety of other 

 practical conditions, fails to achieve its best noise performance. In other 

 words, one may very well not attempt to realize the optimum noise 

 measure directly but use it instead as a guide to detect the onset of 

 diminishing returns in further efforts to improve noise performance. 



