Conclusion
This work presented a 4 × 4 Butler matrix to feed the direction-switched beamforming antenna array for 3.5 GHz 5G wireless application. The desired result was achieved via Computer Simulation Technology (CST). So, the finalised proposed design for BM and antenna array system array was fabricated on single layer Rogers RT5880LZ. The measured result of the BM and antenna array system showed a good agreement compared to the simulated result, which successfully steered radiation beams of -34o, -40o, +32o, and +35o. The overall size of the antenna and Butler matrix was 121mm × 143mm. The result demonstrated that the proposed four-beam antenna array revealed a good agreement for communication system, as well as beam-forming for 5G wireless application.