REGENERATION OF BINARY MICROWAVE PULSES 



87 



ID 



m 

 o 



LU 



a 



D 



3 



o 



-10 



-12 



-14 



-16 



-18 



-20 



-22 



-24 



6 8 10 12 



INPUT LEVEL IN DECIBELS 



14 



16 



18 



Fig. 18 — Static characteristics of the regenerator employed in these experiments. 



f}uired to change the output from zero to maximum. The input level at 

 which this transition takes place is the slicing level and has a very defi- 

 nite value. For a characteristic such as that shown on Fig. 18 this point 

 is not at all definite and the question arises as to how one determines the 

 slicing level for such a device. Obviously this point should be somewhere 

 on the portion of the characteristic where expansion takes place. In the 

 case of the circulating loop the slicing level is the level for which total 

 gain around the loop is exactly etiual to unity. Why this is so can be seen 

 from Fig. 19 which is a plot of gain \'ersus input level for a repeater 

 containing a sheer with a characteristic as shown by curve B of Fig. 18. 

 Amplifiers are necessary in the loop to make up for loss through the re- 

 generator and other components. For Fig. 11) we assume that these 

 amplifiers have been adjusted so that gain around the loop is exactly 

 unity for an input pulse having a peak amplitude corresponding to the 



