Scan performance of infinite arrays of microstrip-fed dipoles with bent arms printed on protruding substrates

E-plane scan results are presented for infinite arrays of microstrip-fed dipoles printed on protruding dielectric substrates. Active impedance values are calculated for dipoles with bent arms and for the array with a near-field dielectric radome cover. It is found that bending the dipole´s arms produces a small improvement in the scan range, as compared to the element with the arms straight, and that a dielectric radome with a low permittivity causes a small shift in the impedance curves. The scan limitation of the array is dictated, however, by the presence of the coplanar feedlines with improvement achievable by varying the substrate´s thickness and permittivity as well as the dipole/feed geometry. A dipole element with a modified coplanar feed design is introduced for wider scan coverage