Investigation on Beam Alignment of a Microstrip-Line Butler Matrix and an SIW Butler Matrix for 5G Beamforming Antennas through RF-to-RF Wireless Sensing and 64-QAM Tests

Abstract

In this paper, an intuitive approach to assessing advantages of beamforming in 5G wireless communication is proposed as a novel try and practical demonstration of importance of alignment between the transmitter’s and receiver’s beams working in millimeter-wave frequency bands. Since the diffraction loss of millimeter-wave signals matters seriously in propagation, the effects of the misalignment and alignment between beams need to be checked for, which was conducted with a horn antenna and the 4 × 4 Butler matrix which mimic the relationship of the base station and handset antennas. Designing and using the microstrip-line and the substrate integrated waveguide (SIW) Butler matrices, RF-to-RF wireless connectivity between the horn and the microstrip line beamformer as case 1 and the horn and the SIW beamformer as case 2, concerning the changing angle of the beam from either of the two Butler matrices, was tested, showing over 12 dB enhancement in received power. This direct electromagnetic link test was accompanied by examining 64-QAM constellations for beam-angle changing from −30° to +30° for the two cases, where the error vector magnitude in the QAM-diagram becomes less than 10% by beam-alignment for the changing angle.

A Miniaturized Multi-Beam Wideband High Gain-5G Antenna Based on a Novel Design of Compact 4x4 Butler Matrix

“…However, the cost and complexity associated with the SIW technique posed limitations. In the same year, a conventional multi-beam antenna structure was fabricated [15]. In this design, the traditional Butler Matrix is made up of two phase shifters, four hybrid couplers, and two crossovers, potentially introducing unwanted effects such as side lobes and insertion loss.…”

Design and Implementation of C-Band Large-Power Planar Butler Matrix in SRS

“…The study of the Butler matrix [7][8][9] involves many aspects, such as the perspective of the frequency band, 77 GHz [3], Ka-band [10], K-band [11], X-band [12], C-band [13], and S-band [13]. From the perspective of large-power design [14], a specific computer-aided method for a large-power Butler matrix design is given [15].…”

Traditional Bulletin Board: Benefits and Drawbacks

“…The majority of gadgets, including computers, cell phones, and cars, can interchange remotely thanks to Bluetooth [14,[37][38][39][40][41][42]. Bluetooth is not supported by the Arduino Uno board alone [43][44][45]. This prevents wireless connections to Android devices, which call for the usage of an interface [46][47][48].…”