SPS Feasability Study SD76SA0239-2

Figure 2.3-8. Amplitron Modified Heat Sink were conducted. A TE?q RCR shown in Figure 2.3-9 was fabricated and tested with results shown in Figures 2.3-10 and 2.3-11. The RCR was uniformly excited for -13 dB peak sidelobe level. Measured sidelobe levels in the E and H planes were -13 dB for good correlation. Off-axis patterns also were taken at predicted higher order mode locations. No existence of higher order mode propagation was found. These tests were performed on a limited scale; however, it definitely proves that the RCR has a potential for a major breakthrough in array technology. Efficiency verification tests will be performed by Rockwell to verify theoretical predictions. Subarray Design Rockwell's design of the MPTS transmit array consists of 7854 subarrays, each 10 meters square. The optimum size of the subarray is a function of the electronic scanning range of the antenna. A small subarray allows more electronic scanning range; however, the total number of electronic scanning circuits increases with the increased number of subarray. With a subarray larger than 10 meters square, the pointing requirements of the subarray is extremely tight, therefore undesirable. The baseline subarray size of 10m by 10m requires the subarray to be pointed to within ± 1 arc minutes for less than 0.5-percent loss. Typical power plots in dB and percent of the subarray is shown in Figures 2.3-12 and 2.3-13. A typical subarray may consist of 20 to 50 RCR's, depending on the power density of the subarray.