The experimental validation of reduced grating lobes in a seven-element, hexagonal, scanning phased array antenna with the one-wavelength element spacing is presented. The base element of the array is a single-layer, dual-mode antenna with self-scanning and nulling properties. For the selected scan angle of -30°, the required microstrip transmission line based feeding network, consisting of ring hybrids, power splitters, and branchline couplers, are designed and developed. A prototype of the complete array and feeding network was fabricated and successfully tested to show the effectiveness of the grating lobe reduction method using the dual-mode antenna elements in scanning phased array antennas with the one-wavelength element spacing.
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