Grating Lobe Reduction in Sparse Scanning Phased Array Through Generation of a Widened Null

This paper explores the use of dual-mode circular microstrip patch antennas to reduce grating lobes in sparse linear arrays with an element spacing on the order of one wavelength through the generation of widened nulls around the location where the grating lobe would otherwise be. This method, combined with a −40 dB Chebyshev window, results in the reduction of the grating lobe and the effective control of sidelobes below −40 dB for scan angles up to 40 degrees.