Millimeter wave beamforming receivers using a Si-based OBFN for 5G wireless communication systems

Since next-generation (5G) wireless communication systems require high-speed processing of large amounts of data and wider bandwidth, the millimeter wave (mmWave) band becomes increasingly important and transmission technologies require a large number of antennas. Therefore, it is necessary to study technologies that can implement a very small antenna considering the characteristics of the mmWave band. In this study, we propose a high-performance miniature analog beamformer implementation technique that can operate in the mmWave band. The proposed method uses silicon (Si) photonics technology, which not only can process large amounts of data at the speed of light, but is also compatible with CMOS processes and can be miniaturized due to high refractive index. The SiN-based optical beamforming network (OBFN) chip used in satellite communications has been redesigned into a Si-based OBFN. In particular, we propose four types of Mach–Zehnder modulator (MZM) structures, including the design used in the existing satellite communication OBFN system. The feasibility and performance were tested with commercial optical simulation software to carry out virtual prototyping and create foundry-ready designs. Simulation results confirm that the proposed schemes are efficient at implementing miniature array antennas in the mmWave band and are suitable for high-performance ultra-small analog beamformers and massive multiple-input multiple-output (MIMO) implementations for 5G wireless communication systems.