Quarter Wavelength Fabry–Perot Cavity Antenna with Wideband Low Monostatic Radar Cross Section and Off-Broadside Peak Radiation

Since antennas are strong radar targets, their cross section (RCS) reduction and radiation enhancement is of utmost necessity, particularly for stealth platforms. This work proposes the design a Fabry–Perot Cavity (FPC) antenna which has wideband low monostatic RCS. While in transmission mode, not only gain achieved, but beam also deflected elevation plane. Moreover, low-profile, i.e., cavity height ~λ/4. A patch designed at 6 GHz serves as excitation source constructed between metallic ground plane superstrate. The superstrate structure formed with absorptive frequency selective surface (AFSS) conjunction dual-sided partially reflective (PRS). Resistor loaded rings serve AFSS, while PRS from inductive gradated mesh on one side to realize phase gradient deflection; other fixed capacitive elements. Results show that RCS was achieved 4–16 GHz, average about 8.5 dB over reference antenna. Off-broadside peak −38° approaching ~9.4 dB. Simulation measurement results presented.