508 



BELL SYSTEM TECHNICAL JOURNAL 



marily in narrow band cases so that for the present we shall concern 

 ourselves only with the first maximum at 9i — ^ and j indefinitely large. 



INPUT TRANSIT ANGLE, e, = j"'^3[— x\' A 



Fig. 6. — Gain-band product dependence on current density (j), with input spacing 

 (xi) fixed. 



M U- 



4.0 

 3.5 

 3.0 

 2.5 

 2.0 

 1.5 

 1.0 

 0.5 

 



377 

 2 



INPUT TRANSIT ANGLE , &, = X|'''3 ( '-^ j"'''3J 



777 



2 



Fig. 7. — Gain-band jiroduct dependence on input spacing (xi), with current density (j) 

 fixed. 



Vari.\tion with C.\tiiode-Grii) Sp.^cing, .Vi 



Now consider that j has been fixed at the largest permissible value 

 according to the previous section and consider the second formulation 



