REGENERATION OF BINARY MICROWAVE PULSES 69 



next repeater. Thus noise and other disturbing effects are completely 

 eliminated and the output of each repeater is identical to the original 

 signal which entered the system. For the case of partial regeneration 

 incoming pulses are retimed and reshaped only as well as is possible with 

 simple equipment. Obviously the difference between complete and partial 

 . regeneration is one of degree. 



One object of the experiment was to determine how well such a partial 

 regenerator would function and what price must be paid for employing 

 partial instead of complete regeneration. The regenerator developed 

 consists simply of a waveguide hybrid junction with a silicon crystal 

 diode in each side arm. It appears to meet the requirement of simplicity 

 in that it combines the functions of amplitude slicing and pulse retiming 

 in one unit. A detailed description of this unit will be given later. Al- 

 though the purpose of this experiment was to determine what could be 

 accomplished in a very simple repeater we must keep in mind that 

 superior performance would be obtained from a regenerator which ap- 

 proached more nearly the ideal. For some applications the better re- 

 generator might result in a more economical system even though the 

 regenerator itself might be more complicated and more expensive to 

 produce. 



METHOD OF TESTING 



The regeneration of pulses consists of two functions. The first function 



is that of removing amplitude distortions, the second is that of restoring 



each pulse to its proper time. The retiming problem divides into two 



[parts the first of which is the actual retiming process and the second 



! that of obtaining the proper timing pulses with which to perform this 



lifunction. In a practical commercial system timing information at a 



[repeater would probably be derived from the incoming signal pulses. 



There are a number of problems involved in this recovery of timing 



pulses. These are being studied at the present time but were avoided in 



the experiment described here by deriving such information from the 



local synchronizing gear. 



Since the device we are dealing with only partially regenerates pulses 

 it is not enough to study the performance of a single unit — we should 

 •like to have a large number operating in tandem so that we can observe 

 'what happens to pulses as they pass through one after another of these 

 Tegenerators. To avoid the necessity of building a large number of units 

 the pulse circulating technique of simulating a chain of repeaters was 

 j employed. Fig. 2 shows this circulating loop in block form. 



