between the microstrip feed line 201 and the h aperture 202 as well as between the microstrip feed line 104 and the h aperture 105 allows a high isolation between the resulting polarizations the size of the h aperture 105 is considerably smaller due to a higher coupling factor in the patch center than the size of the h aperture 202 located near the patch corner the shown structure may in particular use 0 8 mm thick fr 4 feed substrate and a 1 6 mm thick radiator substrate the width of the antenna element including the parasitic patches and substrate may amount to ca 200 mm a height of the antenna including the substrates may amount to ca 9 mm in fig3 a group of graphs 301 show horizontal radiation patterns from port 1 for the primary radiator 106 without parasitic patches narrow beam and a group of graphs 302 show horizontal radiation patterns from port 1 for the primary radiator 106 with parasitic elements wide beam with ripple both groups of graphs 301 and 302 are shown for a frequency range from 2 40 ghz to 2 48 ghz in view of a gain the horizontal beamwidth with parasitic patches i e group of graphs 302 is about 120 degrees at mid band the beamwidth of the primary radiator only i e group of graphs 301 amounts to ca 72 degrees.