3.5 kW wind turbine for cellular base station: Radar cross section modelling and measurement

Due to dramatic increase in power demand for future mobile networks (LTE/4G, 5G), hybrid- (solar-/wind-/fuel-) powered base station has become an effective solution to reduce fossil fuel consumption. Such base stations are powered by small wind turbines (SWT) having nominal power in the range of 1.5-7.5 kW. In the context of the OPERA-Net2 European project, the study aims to quantify and possibly mitigate radio interaction between such SWTs and BTSs. Compared to megawatt WTs, SWTs have the diversity of shape, material and orientation (horizontal / vertical). Thus, a simple representative model (RSWT) was first designed. It is fully metallic to correspond to the worst radio case and its dimensions are scalable to SWT nominal power. In this paper, the RSWT dimensions have been optimized to improve the match of RCS between the RSWT and realistic SWT models having the same nominal power. To verify, comparisons have been done between the RSWT and 3.5 kW Nheowind 3D100 (IDSUD ENERGIES). A scaled prototype of the 3.5 kW RSWT with ratio 1:10 was manufactured. Its RCS as a function of azimuth angle was measured in an anechoic chamber at 9 and 17 GHz with different blade positions. Comparison between simulation and measurement shows a good agreement.