A Power Amplifier for Ultra-High Frequencies

By A. L. SAMUEL E A R E witnessing a r a p i d e x p a n s i o n a n d extension in t h e use of r a d i o c o m m u n i c a t i o n . A c o r r e s p o n d i n g extension in t h e usable p o r t i o n of t h e r a d i o - f r e q u e n c y s p e c t r u m is highly desirable. W i t h t h i s in m i n d , special f o r m s of v a c u u m t u b e s h a v e a l r e a d y been developed for use as oscillators at f r e q u e n c i e s a b o v e 100 m e g a c y c l e s . 1 , 2 E x c e p t a t low p o w e r levels, 3 amplifier t u b e s h a v e n o t b e e n available. * Presented at Institute of Radio Engineers meeting, New York City, October 7, 1936. Published in Proceedings I.R.E., November, 1936. 1 M. J. Kelly and A. L. Samuel, "Vacuum Tubes as High-Frequency Oscillators," Elec. Eng., vol. 53, pp. 1504-1517, November, 1934; Bell Sys. Tech. Jour., vol. 14, pp. 97-134, January, 1935. 2 C. E. Fay and A. L. Samuel, "Vacuum Tubes for Generating Frequencies Above One Hundred Megacycles," Proc. I.R.E., vol. 23, pp. 199-212, March, 1935. 3 B. J. Thompson and G. M. Rose, "Vacuum Tubes of Small Dimensions for Use at Extremely High Frequencies," Proc. I.R.E., vol. 21, pp. 1707-1721, December, 1933.