Broadband high‐efficiency high‐gain dual‐beam empty substrate integrated waveguide cavity‐backed filtenna

Abstract

A broadband high-efficiency high-gain empty substrate integrated waveguide cavity-backed filtenna with dual beams is proposed. The antenna is vertically stacked by three cavities. Two rectangular slots are etched above the uppermost cavity to realize the radiation function. Since the interior of the cavity is covered with metal, the characteristics of the antenna are independent of the used dielectric substrate. The fractional bandwidth of the proposed filtenna is 21.1%, and the efficiency can reach more than 90% in the operational band. The antenna has good frequency selection properties, and the ratio of the −10 dB impedance bandwidth to the −3 dB impedance bandwidth is 0.88. Good gain flatness is obtained, the maximum gain of the filtenna within the operational band is 8 dBi. The proposed dual-beam filtenna can realize broadband and filtering simultaneously, with low cost and high efficiency. It can be used in wireless communication systems.