Broadband cavity‐backed aperture‐coupled vertically mounted strip antenna

A novel cavity‐backed aperture‐coupled antenna having a vertically mounted (VM) strip is proposed, where the signal is fed to the antenna from a microstrip feed through an aperture‐coupled microstrip‐to‐waveguide transition. Broadband characteristics are achieved by the introduction of the VM strip. An equivalent‐circuit model for this antenna that reflects the effects of various structure parameters is proposed. Based on this equivalent circuit, an X‐band antenna was designed by optimizing for broadband, low loss, and highly efficient operation. The measured S11 of the fabricated antenna showed excellent broadband characteristics (47%) and was in reasonable agreement with predictions derived from the equivalent circuit and numerical simulation.