Fig.9. Comparison between simulated and measured S-parameters.
Design switched beamforming antenna array
The switched beamforming antenna array system was based on 4 × 4 BM with 1 × 4 element antenna array. The use of BM is to shift the beam in a different direction; the antenna array connected with BM was presented to develop SAA, as shown in Fig.10. The proposed design of the BM and antenna system operated at centre frequency of 3.5 GHz, respectively. The proposed design 4 × 4 BM have four input and output ports, compact four 3-dB BLC, two crossover structure, and two 45ophase shifters. The use of BM was to shift the beam in different directions. Depending on the input ports (P1, P2, P3, and P4) which fed the output ports to the signal phase (P5, P6, P7, and P8) of the proposed BM, they developed a -45o,+135o, -135o, and +45o phase difference between the output ports. The results of the simulated and measured radiation patterns, obtained by exiting various input ports of the proposed BM, produced four orthogonal beams deposed at -34⁰,32⁰,-40⁰ , and 35⁰, as illustrated in Fig. 10. The four beams steered were 1L, 2R, 2L, and 1R with excited input ports of P1, P2, P3, and P4, respectively.