The best balance between carrier to noise ratio and side lobe performance. Illumination using RP1 The carrier to noise ratio is not as high as above but is in the acceptable range. Side lobe performance is improved. Illumination using RP1 The carrier to noise ratio has been lowered even further and the side lobe performance is improved. Illumination using RP1 The carrier to noise ratio is at the minim and the side lobes are lowest.
Side lobes are the high peaks at the sides of the main peak of the antenna pattern.
Low side lobes are desired. The illumination angle of the primary feed horn, usually between 30 o and 70 o . The angle of the signal beam collected by the parabolic antenna. Larger antennas have narrower beams. The highest carrier to noise ratio, good side lobe performance.