An aperture coupled five element subarray

Aperture coupled microstrip patches have the advantages of more available substrate area for active devices, isolation of the feed structure from the radiating elements, and the elimination of connections through the substrate layers using vias. The authors presented a variation to the single patch design, where four additional patches are added to the single patch and fed by microstrip lines from the center fed patch; this layout is similar to a the probe-fed design of Legay and Shafai (1993). This arrangement offers a convenient way to feed several elements from one slot, although subarraying in this manner does reduce the allowable scan range that is free of grating lobes. This structure has many variable parameters which offer several design choices and the possibility of performance optimization, but this also makes the need for a model paramount.