Tunable Phase Shifters for 6G Beamforming Networks

Abstract

The deployment of 6G network requires multiple number of antennas at the base station with multiple signals that undergo constructive interference to create thinner beams with more energy so as to mitigate path loss. This will support higher data rates, lower latency levels, and improved energy efficiency. This paper proposes a phase-shifting technology for beamforming that focuses radio energy to a specific user equipment, thus maximizing spectral efficiency. We present a novel approach of phase-shifting technology by generating tunable microwave pulses using the slicing-level technique in an optoelectronic oscillator (OEO) setup. Two laser sources undergo intensity and phase modulation using a well-characterized Mach–Zehnder modulator and a phase modulator. Modulating signals in the range of 100 kHz–13.3 MHz are used to generate microwave waveforms. Repetition-rate-tunable pulses are generated from the microwave waveforms using the slicing-level technique. Photonic-assisted tunable pulses generated have a pulse width ranging from 0.6 ns to 7.5 μs and a duty cycle ranging from 17% to 96% optimized for phase shifting (𝜑) of signals, with potential for multiple antenna elements, which act as time delays aimed at creating constructive interference of the beams that form a concentrated beam of energy. This work successfully creates phase shifters ranging from 14° to 299° that can be used to steer antennas for 6G network by controlling pointing angles at the antenna array terminals, which creates a multiplex transmission line as a linear combination of signals.