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The plots shown here are from an analysis of a square 16-element microstrip patch array. In order to steer the antenna main beam off
boresight, a progressive phase delay has been applied to the element feeds of the rows of the array. The columns are fed in-phase. The geometry of the array is shown
in Figure 1. Probe feeds attached as indicated by downward-pointing triangles.
Radiation Intensity for the magnitude of all polarizations with no beamsteering applied are shown
in Figure 2 for two principal plane pattern cuts. The cuts are in the elevation plane, with the X-symbol indicating cuts in the plane of the array rows, and the o-symbol indicating a cut in the plane of the array columns.
For the total of all polarizations, the surface plot of the radiation pattern over all of visible space is shown
in Figure 3, normalized to directive gain. Surface plots can also be displayed normalized to
an isotropic radiator (dBi), to an arbitrary scale factor, or in absolute gain
(W/Sr) format.
If a progressive element-to-element phase is applied to the columns of the array,
the pattern above changes to show the beamsteered pattern in Figure 4. This
shows a shifting of the pattern on the principal plane cut aligned with the array row dimension, which is consistent with the condition of column-wise phase shifting. Since the row-wise phasings of the array do not advance (from row to row), this pattern cut remains unchanged, and aligned on boresight. However, the cut shows reduced radiation due to the fact that the overall pattern maximum is no longer aligned along this cut.
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