Low-Profile Multi-/Wide-Band Fabry-Perot Cavity Antenna under Single-Layer Based on Series and Parallel LC Resonant Circuits

In this letter, a series of low-profile multi-/wide-band high-gain Fabry-Perot Cavity Antennas (FPCAs) are designed by utilizing the mutual coupling between metamaterials (MMs) on the upper and lower surfaces of a single-layer dielectric substrate. Three types of MMs units with simple structures are constructed based on equivalent circuit models, which are then combined to form the desired multi-/wide-band partially reflective surfaces (PRS). Compared to conventional antennas that can only achieve dual-band resonance in a single-layer dielectric substrate with a profile height approximating 0.5λc, this approach achieves dual-/tri-band resonance characteristics of the PRS with controllable frequency ratios. Finally, a tri-band high-gain FPCA with a Vivaldi antenna as the exciting source is fabricated. Measurement results demonstrate that the antenna exhibits good impedance matching, with maximum gains of approximately 13.0 dB (7.7 GHz), 16.1 dB(9.6 GHz), and 15.4 dB(11.07 GHz), respectively