Split aperture decoupling method applied to multi-beam pillbox antennas for large coverage, high crossover and low side lobe levels

The "Split aperture decoupling" method is applied for the first time to the multi-beam pillbox antenna. This method allows simultaneously a large angular coverage, high crossing level and low side lobes levels (SLLs) for a lossless multi-beam antenna system. To validate the proposed concept a SIW (Substrate Integrated Waveguide) pillbox antenna with two radiating apertures was designed at 24.15 GHz and fabricated with a standard PCB fabrication process. The measured results of the realized prototype are in good agreement with the simulated ones. The antenna has very good scanning performance with a large angular coverage of ± 40 high crossing level between the beams around -3dB and SLLs lower than -11dB over the whole scanning range. The fractional bandwidth for VSWR <;2 (S11 <;-10dB) is 2.5%. The gain of the center beam is 24.2dBi with a radiation efficiency of 54%.