32 BELL SYSTEM TECHNICAL JOURNAL 



From Table III 



ttA = 1.50 a = 5.4 10~*p neper/w 



Case 1 : X fixed at 0.01 m 



Oopt = 0.08 m 



Uopt = 2.76 10~^p neper/meter 



Case 2 : a fixed at 0.05 vi 



\opt = 0.0097 w 



"opt = 5.36 10~V neper/w 



Assuming sinusoidal bends with a 0.42° maximum deviation, the attenua- 

 tion of centimeter waves can be reduced to one half by increasing the wave 

 guide radius from 5 to 8 cm. For a 5 cm wave guide radius, 1 centimeter 

 wavelength is close to the optimum. 



