Aperture-Coupled Patch Antenna With Flat-Top Beam for Microwave Power Transmission

This letter presents a flat-top radiation transmitter (Tx), which is composed of 2 × 2 array patches connected to the ground plane of the aperture by four shorting vias, which can generate a mushroom structure resulting in back lobe level reduction. The final design exhibits an overall size of 1.93λ ₀× 1.93λ ₀× 0.075λ ₀at 5.8 GHz. The measured results agree well with the simulated results, which achieves a maximum left-hand circular polarization gain of 8.5 dBi with a sidelobe level of$< $−13.5 dB, and 3 dB beamwidths of 80∘in both theE-andH-planes. Moreover, the proposed transmitter is tested with the rectenna showing that a stable received energy of 5.93 mW is obtained with an exciting 1 W input power in case of receiving antenna lateral misalignment of up to 60 mm, which demonstrates feasibility in practical deployment. Compared with the other works, the proposed antenna has the advantage in compactness and wide 3 dB beamwidth.