Miniaturized 4 x 4 switched-beam butler matrix with bandwidth enhancement for 5G communication system

• Main Authors: Mahyuddin, Nor Muzlifah, Mohd Suhaimi, Nazleen Syahira, Ismail, Widad, Mohd Ibrahim, Imran
• Format: Article
• Language: English
• Published: Elsevier B.V. 2022
• Online Access: http://eprints.utem.edu.my/id/eprint/27012/2/MINIATURIZED%204%20%C3%97%204%20SWITCHED-BEAM%20BUTLER%20MATRIX%20WITH%20BANDWIDTH%20ENHANCEMENT%20FOR%205G%20COMMUNICATION%20SYSTEM_COMPRESSED.PDF; http://eprints.utem.edu.my/id/eprint/27012/; https://pdf.sciencedirectassets.com/270704/1-s2.0-S1110016822X00070/1-s2.0-S1110016822004665/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjENv%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJIMEYCIQDIU6gypes1DII0v9itW4uGZUheZV85OCkia%2FYH76z6fwIhAMzxkJcy273nZHU1hCf1oehfJRnnP0yz8ZhQwDpfSYNwKrMFCFQQBRoMMDU5MDAzNTQ2ODY1IgxkkQKrb1TePAgB1%2BkqkAW4ABpw6qcey06I7Y9In3sRIo7jTov3X7g%2BxEBGryrAnQlzRKsAna%2BMeMP2x%2FiW5lucWTtQau%2FdvN0%2BBSnGncrMg6y%2BRSUaqjb0yKxdEZJAJeNaarM3UBj1NGitUh0UfMQCQlzTwA3L7UM3%2FiGi6FpiQmdHa4lUX1kT9W7FY4NO3z0Kn5MuxCkWNEyQHG6Egi242z5eZ%2FpgsKmPjaVFqbv%2B77AVY6O9Uv8jg9gGGqeJKjhh9nSKVC3yiC7dnsdcZBmS%2B9qzsaw27cvR%2FHIuMYl2RCUEJ%2Bn7Z6RfnlVfqPEFK59QP%2Fmvj8fBQGccmVk6E9CIniAu8r9iHkxJurxT7mQ3xJdgDcYj8D8cxz9t1njeq8hckIRrYeyRW2JKFfqO%2BQl0N7DYlY%2BEB4gP1gPV63Rp4aOQ8ZlEtLdCJUiEOAQDTNl6PvekO%2FY3G341uUeM%2F6Vz%2Fb21OtkmIQHQ4N7nrxTiCTQRuxa9%2BJdCI9TPzYzkvkS%2BH3TXCUMcUs%2BTFH%2FcOXZQi1zKl7q08E0UhClygI3kqIpgqbDh9ooYL6WaLWqGpfiF2xQ892MoaG2swQ0sYWo0bzWd7RSsyvBk%2FTTeX6ebTtay4LVGHXvSPjhW4ERiEGN7nPlFiBvb7F1Q9nWOYB2qdxwl7zGQgXZixdYS1Vpet1ZJ7%2BpljJI6VR3fJCiSiewD58%2FPOrh1IAgw05QHvpKSjqeZU7UpBld547PWnTYxy%2BtKtAeuJwui9sAn0Vumc2%2FAaUt5U8O4dpBmOIHyGf%2FFBFIV%2F1ezeOMTC4RJsgpHAJVz1S3U6u3%2BeMd813DX346odbxjIerg8TU6B06ITKxlvA5C3oaX1I6ZGZQniTHWrbSn39exhMV4kiKFoucH%2BzCJ0umrBjqwAWi8XJXzzOro62zhRknuH%2BKZdU%2B%2BqXsi%2Bd9j%2Fzaf10vYUZADvusQwbsvLplgqy2EygMRQR%2Fbv9fciJ2TsKI%2B1qj7SQfZwuO9Fh3svLelvaZHfCCjZYa6fRyAGpFeuvUr%2FIDI%2FHw2Ulcxl0halrs5vZEXadmc2wu%2F%2Fs8BzmrTnDE9Ro8dL0onUSTn3QCyg9KqJe5VmrBC6udeUbu7%2FJtO5wq%2BRPyoGk4rklKsMIf5zOhI&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20231214T032559Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY3ANG32JQ%2F20231214%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=f1833a39afdc1168ef572f1cd29de011700b060a18e4e77716d1bc34041ec5ac&hash=dd948f2fa8f8b2aaf19f01add9599a921f5d24ad3e2683747afa6680a50c32ad&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S1110016822004665&tid=spdf-f065b107-d1cc-4975-9392-ab0d64cb100a&sid=55f2a40591ea064aa65893128d8587db1a14gxrqb&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=171f5b5c565c5556070455&rr=835357bd2f0413e1&cc=my; https://doi.org/10.1016/j.aej.2022.07.014
• Institution: Universiti Teknikal Malaysia Melaka

A 4 x 4 Butler Matrix (BM) without phase shifter is proposed to provide bandwidth enhancement and size reduction by removing a conventional 0 dB/90⁰ crossover, two 0⁰ phase shifters and two 45 phase shifters. Two proposed 3 dB/45⁰ patch couplers replace the combination of two conventional 3 dB/90⁰ branch-line couplers and two 45⁰ phase shifters, whilst a modified0 dB/0⁰ crossover removes two 0⁰ phase shifters from the conventional BM. The -10 dB fractional bandwidths of reflection coefficients and isolations for the proposed BM are 18.46% in simulation and measurement. The -6 dB ± 1.5 dB average transmission coefficient and +45⁰, �135�, +135⁰and +45⁰ of output phase differences with 1.8� average phase imbalance are accomplished at 6.5 GHz. The simulated and measured scattering parameters (S parameters) and phase differences are in close compliance with each other. Four switched-beams pointed at +15⁰, -50⁰, +50⁰ and +15⁰ are developed by integrating the proposed BM with inset feeding patch antennas. The proposed BM is miniaturized by 51.56%, whilst the bandwidth performance is enhanced by 9.7% compared to the conventional BM. Hence, this compact BM is a promising candidate for the fifth generation (5G) communication system.