Closely Spaced Series Fed Tapered Arrays for Base Station Massive MIMO Application

In this paper, series fed tapered array antenna for base station massive MIMO (m-MIMO) application is proposed. A 5-element series fed array is considered as an antenna sub-array element for proposed m-MIMO antenna system. The sub-array elements are tapered uniformly with respect to center element to reduce side lobe level and mutual coupling from adjacent sub- array. Simulation for two and eight element m-MIMO design prototype is presented. A two-element m-MIMO prototype is fabricated and measured for validation. A very closely spaced (0.08λ
₀
) sub-arrays offer mutual coupling less than -20 dB, azimuth and elevation half-power beam width of 105° and 30° respectively and side lobe level less than -20 dB.