Subwavelength Substrate-Integrated Fabry-Pérot Cavity Antennas Using Artificial Magnetic Conductor

This paper presents the high-gain low-profile subwavelength substrate-integrated Fabry-Pérot (FP) cavity antennas with artificial magnetic conductor (AMC) sheets. A partially reflective planar AMC sheet and a ground plane are used as the two reflectors of the FP-type resonant cavity for an ultra-thin planar design. The cavity is fully filled with dielectric substrate for further reduction of thickness of the antenna and easy integration. A microstrip patch antenna is embedded into the cavity as a feed. As design examples, the antennas are designed to operate at 10 GHz with a fixed overall thickness of λ₀/9 (where λ₀ is the operating wavelength in free space) and an aperture of 2λ₀ × 2λ₀. The losses caused by both dielectric and conductors are analyzed, which are critical for a fully dielectric substrate antenna design. The via-walls surrounding the radiating aperture are introduced to improve radiation patterns and gain by suppressing the surface waves, which are another critical loss for a thin fully dielectric substrate antenna design. Measured results show that such dielectric-integrated subwavelength cavity antennas feature the high gain of 12.5 dBi, low profile, easy integration into circuit board, and mechanical robustness, which makes them suitable for low-cost mass production.