Phased-Array Antenna Patterns (Part 6)—Sidelobes and Tapering (.PDF Download)

Previously in this series, we introduced the phased-array concept, beamsteering, and array gain. Then we presented the concepts of grating lobes and beam squint. In this final part, we will discuss antenna sidelobes and the effect of tapering across an array.

Tapering is simply the manipulation of the amplitude contribution of an individual element to the overall antenna response. Earlier in the series, no tapering was applied and the first sidelobes were –13 dBc as seen in the figures. Tapering provides a method to reduce antenna sidelobes at some expense to the antenna gain and main-lobe beamwidth. Following an introduction to tapering, we will elaborate on a few points relative to antenna gain.