Wideband cavity-backed log-periodic-slot end-fire antenna withrnvertical polarization for conformal application

摘要

A 6–18 GHz wideband cavity-backed log-periodic-slot end-fire antenna with verticalrnpolarization for conformal application is presented. The log-periodic folded slots andrnparasitic slots with 10 slot elements are applied to cover 6–18 GHz frequency bandrnand the log-periodic metallic cavity is placed under each slot element to keep widebandrnperformance and prevent the effects of large metallic carrier on radiationrnpatterns. The ground plane etched with log-periodic slots is reversed and touchedrndirectly to the backed cavity and a dielectric cover is added to the antenna, to furtherrnimprove the antenna performance. Meanwhile, a broadband microstrip-coplanarrnwaveguide transition is inserted in the antenna for measurements. With these designs,rnthe proposed antenna shows good impedance matching (|S_(11)|<27 dB) and end-firerngain (>4 dBi) performances in 6–18 GHz. The proposed antenna also keeps low-profilernand easy flush-mounted characteristic which is suitable for conformalrnapplications of high speed moving carriers.