Non-homogeneous Fabry-Perot Antenna Design Process to Improve Aperture Efficiency

A novel technique to design Fabry-Perot antennas with non-homogeneous partially reflective surfaces (PRSs) is described. It uses a transmission line circuit model to efficiently obtain all necessary unit cell designs that satisfy the cavity resonance condition. This method allows an increase in directivity without reducing the bandwidth for a given footprint. Some design examples in the Ku-band are presented, showing the evolution from a simple single-layer PRS to a non-homogeneous two-layer one. The latter achieves an increase of about 3 dB in directivity while maintaining the bandwidth in electromagnetic simulations. This way, the gain-bandwidth product is improved from a value of 5 to almost 9, effectively raising the antenna efficiency.