Compact ridged substrate integrated waveguide cavity backed slot antenna

A compact ridged substrate integrated waveguide (SIW) cavity backed slot antenna (CBSA) is proposed and implemented for a massive MIMO base station antenna system with very high spectral efficiency. The ridge of the SIW cavity is adopted to reduce the volume of the CBSA and the transverse slot length on the cavity. The size of the cavity is about 35 mm × 25 mm × 2.12 mm (corresponding to 0.31 λ₀ × 0.22 λ₀ × 0.019 λ₀). The measured results are in very good agreement with the simulated data. The proposed compact antenna is suitable for the massive MIMO array system by providing high efficiency and low mutual coupling array performance.