Sub-array Design Diagnostics for the Development of Large Uniform Arrays

The use of sub-arrays has been a popular approach in the design of large array antennas. Using sub-arrays simplifies the array design by allowing the designer to concentrate on the smaller sub-array and repeating it throughout the rest of the array. Anomalous grating lobes have been shown to appear in large uniform arrays caused by systematic errors in the design of sub-array. Thus, it is important for the sub-array designer to be able to diagnose errors in the sub-array design before incorporating it into the larger array. This paper will categorize and demonstrate specific sub-array pattern distortions that can cause grating lobes to appear in uniform arrays. In addition, a design example will present how recognition of the aforementioned distortions can be used to diagnose and prevent the appearance of grating lobes. This will be done by showing the design process of a 1x16 linear array design that uses four 1x4 sub-arrays. Its design progress will include analytical, full-wave simulation, and measurement parts.