This applet demonstrates how the array elements and positioning affect the gain and beamwidth performance of an array antenna.
The element beamwidth is varied by adjusting the relevant aperture (Width, Height) scrollbar and there is a choice of either sin(x)/x or Gaussian element beam shapes from the drop-down menu.
The upper left display models the element gain and beam pattern.
The lower left display indicates chosen array geometry.
The third and largest plot on the right displays the element (blue) and resulting array (red) beam pattern. Both plots are normalized, and the key performance values are updated in text below the beam plot. Linear (voltage) or Power (dB) plot alternatives are chosen by the radio buttons.
Moving the mouse in the beam pattern-angle space, displays the boresight relative sidelobe level and is related to the mouse x-axis positional value.
Horizontal and vertical array size, element aperture and spacing are modified with the relevant group of scrollbars. Either linear or parabolic tapers are available, quantified by the edge element roll-off. The drop-down menu provides choice between a zero-loss taper profile feed network or a simple resistive-loss taper profiler. Zero feed loss is assumed for one or two element arrays.
Azimuth or elevation pattern plots are selected in a drop-down menu.
The angle scale scrollbar improves the angular resolution and the accuracy of beamwidth measurement.
Default values may be modified and the display updated using the relevant scrollbars.

User Notes:
The applet default values are close to an optimum design. Explore the effect of changing the element size, spacing and taper.
The assumptions made in this analysis include an ideal element antenna with no losses.
Grating lobes arise if the element spacing significantly exceeds the element aperture.