Grant: Discovery Grants Program - Individual

Future communication beyond 5G (6G) would reach Tbps of throughput level for up to 1 km range with flexible user mobility. Thus, above 100 GHz bands (W-/D-band and sub-THz) are in consideration for such applications requiring high gain efficient mmWave antenna systems with intelligent beamforming capable of compensating for the considerable free-space path loss, material losses, and the reduced power generation of active electronic devices at these frequencies. The challenge in designing wide beam scanning large phased arrays is mainly related to the element size and the required spacing between the elements, making it difficult to use conventional beamforming networks. As the elements become physically small, high accuracy is required, which cause higher manufacturing cost. Thus, unconventional architectures are required using hybrid techniques such as subarray modules and quasi-optical feeding that are still challenging to use above 100 GHz. The gap waveguide technology feeding based on low-bit phase shifters and parasitic subarray with lower bit control phase would reduce the complexity and cost. In addition to the large mmWave phased array antennas, the program will consider the following problems that are in demand: Design massive MIMO (mMIMO) arrays in a compact form by implementing the overlapping subarrays-such a design deals with contradicting requirements of the MIMO concept. On the one hand, the mutual coupling between the subarrays should be minimized, but overlapping subarrays imply stronger coupling. However, dual-polarized overlapping elements with orthogonally polarized subarrays. Design Reconfigurable Intelligent Surfaces (RIS), which would be necessary for mmWave communication to redirect the signal to one or more directions to avoid the blockage of the signal due to the various obstacles between the base station and users in the outdoor/indoor environment. Much research is done by antenna and communication engineers regarding small and large RIS. Such a high-demand problem still lacks simplicity and low cost. A simple direction of arrival (DoA) will be proposed, and each reconfigurable status will be used for multiple scenarios to simplify and speed up the reconfigurability utilizing the Artificial intelligence (AI) and machine learning (ML) approaches. Orbital Angular Momentum (OAM) antennas were proposed for short transmission of massive data. However, simultaneous OAM multimode transmission and reception are complicated to realize, particularly for large apertures. The concept of radial travel wave antenna will be used as subarrays of a radial array to form a circular array with the required OAM phase distributions. To reduce the beam divergence, the traveling wave array will be designed with a beam tilted toward the center of the circular array axis. The proposed program addresses several challenges in designing mmWave wave antennas, leading to efficient future wireless communication systems.