pei-yuan qin

3D-Printed GRIN Lens Array for Hybrid Beamforming: Design and Experimental Validation

Beamforming antennas are a critical enabling technology for satellite ground terminals, particularly for low Earth orbit (LEO) communication systems that require fast, continuous, and wide-angle beam steering to track rapidly moving satellites. Conventional digital beamforming architectures provide fine-grained control over beam direction, amplitude, and phase at each antenna element, enabling high flexibility and adaptive beam management. However, their reliance on a dedicated radio-frequency (RF) chain and baseband processing for every element leads to prohibitive power consumption, system complexity, and implementation cost, especially for large-aperture, high-gain arrays. In contrast, purely analog beamforming solutions, such as phase-shifter networks, feeding matrices, and lens-based antennas, offer lower cost and improved energy efficiency but are limited in beam agility, scalability, and multi-beam operation, and often face challenges in suppressing grating lobes and supporting wide-angle scanning in compact form factors. This talk will review different beamforming technologies, with a focus on hybrid beamforming. It will introduce a hybrid beamforming antenna architecture that integrates gradient-index (GRIN) lens arrays, RF switching networks, and digital baseband processing to combine the advantages of both analog and digital beamforming. The GRIN lens array performs first-stage spatial beamforming in the analog domain, generating multiple high-gain, narrow beams with high aperture efficiency, while the digital beamforming stage provides flexible beam selection, complex weighting, and fine beam steering. A beam-interleaved strategy is introduced to effectively suppress grating lobes in large-aperture lens arrays, enabling robust one-dimensional and two-dimensional beam scanning without imposing strict physical constraints on subarray placement or feed optimization.

The talk will also present experimental results from a fabricated multi-lens prototype, demonstrating high realized gain, low scanning loss, and sustained sidelobe suppression across a wide field of view, validating the feasibility, scalability, and energy efficiency of the proposed approach. These results confirm the suitability of the architecture for next-generation satellite ground terminals, particularly for high-gain, wide-angle, and agile beam tracking in LEO satellite communication systems.

Pei-Yuan Qin received the B.E. degree in electronic engineering from Xidian University, Xi’an, China, in 2006, and the joint Ph.D. degree from Xidian University and Macquarie University, Australia, in electromagnetic fields and microwave technology in 2012. Since 2026, he has been a Professor with University of Technology Sydney (UTS), Australia. His research interests include reconfigurable antennas, antenna arrays, and microwave components. Dr Qin was awarded an Australian Research Council (ARC) Discovery Early Career Researcher Award in 2017. He is currently leading multiple Australian government and industrial projects. His team’s research has won many awards, including 2016 Computer Simulation Technology (CST) University Publication Award, Best Paper Award in 2019 ISAP, Best Paper Award in 2023 Australian Microwave Symposium, and etc. Dr Qin has served as General Co-Chairs for 2022 IEEE International Symposium on Antennas and Propagation (ISAP) and 2019 Australian Microwave Symposium. He is currently severing the Associate Editor of IEEE Transactions on Antennas and Propagation and IEEE Open Journal of Antennas and Propagation. He is the founder and Chair of Australian Node - Antenna Measurement Techniques Association (AMTA).