26 



BELL SYSTEM TECHNICAL JOURNAL 



given frequency, a compromise must be effected between these two impor- 

 tant performance factors. Because of increased condenser by-pass action a 

 smaller area must be used to obtain a given conversion loss at a higher fre- 

 quency. For this reason the power handling ability of units designed for 

 use at the higher frequencies is somewhat less than that of the lower-fre- 



II) — 



- > 



uj O 

 Q. t 



-I UJ 



2i 

 <l 



UJ Z 



<< 



100 

 80 

 60 



0.02 



0.04 0.06 0.1 0.2 0.4 0.6 0.8 1.0 



APPARENT CONTACT AREA IN SQUARE INCHES 



XIO" 



Fig. 13- 



-Correlation between power handling ability measured with microsecond radio 

 frequency pulses and contact area in silicon crystal rectifiers. 



quency units because emphasis has been placed upon achieving a given sig-- 

 nal-to-noise performance in each frequency band . 



Use of the improved materials and processes produced rather large im- 

 provements in the d-c rectification ratio, conversion loss, noise, power 

 handling ability, and uniformity. Typical direct-current rectification char- 

 acteristics of units produced by both the old and the new processes are shown 

 in Fig. 14. These curves show that reverse currents at one volt were de- 

 creased by a factor of about 20 while the forward currents were increased by 



