The main lobe of the antenna can be steered electronically within a limited angle by phase shifting the drive signals applied to the individual elements.
22.
The advantage of the Hann window is very low aliasing, and the tradeoff is slightly decreased resolution ( widening of the main lobe ).
23.
This reduces radar sensitivity at certain radial velocities, but MTI allows the main lobe of the antenna beam to be aimed closer to the ground.
24.
In all cases, the close-in sidelobe levels are consistently high, at about-13.5 dB relative to the main lobe.
25.
However, the various windowing functions do perform differently from one other, with some giving main lobes which are unnecessarily broad for the sidelobe levels achieved.
26.
There is also usually a backlobe, in the opposite direction to the main lobe, due to the spillover radiation from the feed antenna that misses the reflector.
27.
The radiation pattern is unidirectional, with the main lobe along the axis perpendicular to the elements in the plane of the elements, off the end with the directors.
28.
While settlements within the main lobe receive enough energy, the energy received by the settlements between the main lobes may be "'6 dB "'less.
29.
While settlements within the main lobe receive enough energy, the energy received by the settlements between the main lobes may be "'6 dB "'less.
30.
When different delay and sum beamformers are applied to each frequency bin, the result is that the main lobe simultaneously points in multiple different directions at each of the different frequencies.
