418 



BELL SYSTEM TECHNICAL JOURNAL 



Table III.— Values of the Bessel Function Zero {ri„,) for the First ISO Modes in a Circular 



Cylinder Resonator 



* Nomenclature after Barrow & Mieher, "Natural Oscillations of Electrical Cavity Resonators' 

 IRE Proceedings, April 1940, p. 184. M modes take zeros of Ji{x); E modes take zeros of J,{x) 

 Number directly following E or M is /; number after hyphen is number of root. 



Values less than 16.0 are abridged from six-place values and are believed to be correct; value 

 more than 16.0 are abridged from five-place values and may be in error by one unit in fourth decima 

 place. 5 in fourth place indicates that higher value is to be used in rounding off to fewer decimals 



One solution, of limited application, is to choose an operating rectangle 

 free from extraneous responses. An alternative solution is to design the 

 cavity in a manner such that the undesired responses are reduced or sup- 



