A 6–18 GHz cavity-backed log-periodic-slot end-fire antenna for conformal application

A 6–18 GHz log-periodic slot-inspired cavity-backed end-fire antenna for conformal application is proposed in this paper. The log-periodic structure with 10 slot elements is applied to cover 6–18 GHz frequency band and the metallic cavity is placed under each slot element to keep wideband performance and prevent the effects of large metallic holder on the radiation pattern. A dielectric cover is used to improve the antenna performance and a broadband microstrip-CPW transition are inserted in the antenna as the feeding network. With these novel designs, the proposed antenna shows experimentally a good return loss and end-fire gain performances in the frequency range of 6–18 GHz. The proposed antenna also keeps low-profile and easy flush-mounted characteristics.