An Investigation of Dual-Band Fabry-Pérot Resonant Cavity Antennas

In this dissertation, we examine a dual-band version of the Fabry-Pérot resonant cavity antenna that uses a frequency selective surface (FSS) patch layer over a ground plane to form a composite artificial ground plane that replaces the single metal ground plane of the conventional structure. The structure thus consists of an upper cavity region (between the FSS and the partially reflective surface, also known as the PRS) and a lower cavity region (between the ground plane and the FSS). The conventional single-cavity Fabry-Pérot antenna is studied first, and the theory is then extended to the proposed dual-band structure. The 2-D arrays of metal patches that form the FSS and PRS layers in the proposed dual-band design are first considered to be suspended in air for simplicity. An iterative design procedure is given that determines the optimum resonance frequency of the PRS periodic structure as well as the optimum location of the FSS layer within the composite cavity and the optimum source locations. The PRS and FSS are then placed on 60 mil thick Arlon Diclad 527 boards and the structure is once again optimized for dual-band behavior. The study is further extended to a practical truncated Fabry-Pérot antenna of size 6 in x 6 in. Results for this practical dual-band structure are shown and these results are compared with those obtained using the commercial simulation software Ansys Designer.