CARAMBA I 



The lens-feed and radiating-array system is designated as CARAMBA I. 3 

 The lens is a parallel-plate R-2R device which places the correct phases at the 

 array elements when the lens and array radii are in a 1:2 ratio. Placed about one- 

 quarter wavelength from the lens periphery are 64 input-output probes. Four of 

 the probes are used simultaneously as inputs, and fed with a 1-2-2-1 amplitude 

 taper. The lens output probes for 32 elements are connected to the radiating ele- 

 ments by means of equal-length cables. 3 ' 6 By feeding more than one of the input 

 probes at one time, the energy propagated through the lens is highly directive, and 

 is removed at the diametrically opposite output probes with a taper, to produce low 

 side lobes in the radiation pattern of the array. A typical array schematic is shown 

 in figure 45 and radiation patterns for a four-probe tapered input are given in fig- 

 ure 46. The beam is scanned in azimuth by means of diode switches at each lens 

 port and by additional circuitry to maintain the proper input-probe taper. The sys- 

 tem is operable over a 20-percent frequency band. 



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