Low-profile wideband antenna with unidirectional inclined radiation pattern for C-band airborne applications

An original single layer low-profile planar microstrip antenna is hereby presented for airborne C-band applications. The antenna structure, endowed with a dual microstrip feed and quarter-wave parasitic patches, provides a flexible design on a 787 ¿m thick dielectric substrate. Simulated characteristics of 15.4% impedance bandwidth at 7.1 GHz are reported with a low-frequency dependent inclined unidirectional radiation pattern with a minimum gain value of 5 dBi over the entire band. The wideband performance is explored by investigating the electromagnetic coupling between the parasitic patches and the driven patch while the inclined radiation is obtained by exploiting the beam squint of the quarter-wave patches in the E-plane.