Experimental Radiation Patterns, SAMB Time-Delay System 



A composite pattern of the 32 beams of the true-time-delay system is 

 shown in figure 25. Note that in this case 32 beams are required to adequately 

 cover the sector, since less beam-broadening occurs for this system. These pat- 

 terns were taken over a 50-percent frequency band, to permit determining the 

 extent of pattern deterioration with bandwidth. Figures 26 through 44 show beam 

 1L near broadside and beam 16L approximately 45° off broadside. Figures 27 

 through 33 show that beam 1L has side lobes no higher than -20 dB over about a 

 40-percent band, and that there is little deterioration in the main beam shape. 

 Beam 16L, as shown in figures 36 through 40, has side lobes lower than -20 dB 

 over only a 25-percent frequency band, and the beam deteriorates rapidly beyond 

 the limits of 0.8 f and 1.05 f . Note, however, that the position for a given beam 

 is constant over the frequency range, a characteristic of the true-time-delay method 

 of scanning. 







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Figure 25. SAMB time-delay array patterns, 45° sector coverage, f - 



23 



