Metamaterial-Based Low-Profile Broadband Aperture-Coupled Grid-Slotted Patch Antenna

A metamaterial-based broadband low-profile grid-slotted patch antenna is presented. By slotting the radiating patch, a periodic array of series capacitor loaded metamaterial patch cells is formed, and excited through the coupling aperture in a ground plane right underneath and parallel to the slot at the center of the patch. By exciting two adjacent resonant modes simultaneously, broadband impedance matching and consistent radiation are achieved. The dispersion relation of the capacitor-loaded patch cell is applied in the mode analysis. The proposed grid-slotted patch antenna with a low profile of 0.06 λ₀ (λ₀ is the center operating wavelength in free space) achieves a measured bandwidth of 28% for the |S₁₁| less than -10 dB and maximum gain of 9.8 dBi.