A Flat-Top Beam H-Plane SIW Horn Antenna Based on Beamforming

This letter presents a flat-top beam H-plane substrate integrated waveguide (SIW) horn antenna. The radiation from the SIW H-plane horn antenna aperture can be regarded as magnetic current radiation. To obtain the desired radiation patterns, the phase and amplitude distributions of the magnetic current of the horn aperture can be calculated theoretically. By changing the length and deflection angle of the metal-via arrays, the magnetic current distribution on the aperture can be adjusted, and it is consistent with the theoretical calculation. To verify the proposed method, an SIW horn antenna is designed, fabricated, and measured. The measured results are in good agreement with the simulated ones. The proposed horn antenna obtains a flat-top beam in the angle range of ±40 degrees, and the fluctuation is less than 1 dB.