https://scholarworks.unist.ac.kr/handle/201301/38 2026-05-01T01:24:24Z https://scholarworks.unist.ac.kr/handle/201301/91608 Title: Compact Differential Power Dividers With Arbitrary Complex Terminations for 6G FR3Communication Author(s): Jung, Jaehwan; Kim, Taehyeon; Kim, Hyungju; Kong, Sunwoo; Lee, Hui-Dong; Park, Bonghyuk; Park, Jinseok; Lee, Seungchan Abstract: This article presents compact N-way power dividers to address the size and impedance limitations of the quarter-wavelength transmission line-based power divider. In this work, we employ an even-odd analysis to separate the design of the power-transmission network from the port-isolation network. This approach enables the derivation of rigorous closed-form design equations for arbitrary complex source and load impedances' matching networks. As proof-of-concept (PoC), two types of power dividers (C-L and L-C types) were implemented targeting 6G Frequency Range 3 (FR3) upper mid frequency bands. The C-L type divider achieves an insertion loss of 0.85-1.52dB and isolation of 15.5-33.1dB across the 12-18GHz. The L-C type divider exhibits an insertion loss of 0.76-1.16dB and isolation of 16.1-31.1dB over the 7-11GHz. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91571 Title: Efficient Design Method for an FF-CSCC Active EMI Filter for High-Noise Inverter-Fed Motor Drives Author(s): Kang, Dongwan; Jeong, Sangyeong; Park, Ayeon; Kim, Jingook Abstract: This paper presents an efficient design guideline for feedforward current-sensing current-compensation (FF-CSCC) active electromagnetic interference (EMI) filters targeting high-noise inverter-fed motor drives. Shielded cables between an inverter and motor can significantly increase conducted emission (CE). Under high-noise conditions, the current amplifiers used in an active EMI filter (AEF) lead to performance degradation due to reduced current gain. To prevent this, an effective mitigation strategy is to employ multiple parallel AEF modules. However, inverter-fed motor drives operate at a fundamental switching frequency lower than the CE regulation band, resulting in inefficient compensation of signals that do not require attenuation. To address this, this paper introduces a high-pass filter (HPF) at the sensing stage to block irrelevant low-frequency components. Although the HPF effectively attenuates low-frequency noise, it also causes phase leading, which degrades AEF performance. To compensate for this and improve performance, it also proposes a phase compensation circuit (PCC). Experimental results confirm that the proposed HPF and PCC significantly reduce the number of AEF modules required for CE compliance. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91456 Title: Guest Editorial: Special Cluster on Artificial Intelligence in Design, Optimization and Measurement of Antennas and Periodic Structures Author(s): Lin, Wei; Zhao, Luyu; Huang, Guan-Long; Song, Chaoyun; Byun, Gangil; Tomura, Takashi 2025-10-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91386 Title: Spot Beam Power Optimization for an Energy Efficient Multi-LEO Satellite Network Author(s): Moon, Jihwan; Lee, Hoon Abstract: This paper proposes a spot beam power control method for downlink non-terrestrial networks consisting of multiple low Earth orbit (LEO) satellites. Each designated ground access point (GAP) is continuously served by a steering beam from LEO satellites during their visibility period. We address the global energy efficiency (GEE) maximization task to determine the optimal tradeoff between the sum-rate and total power consumption of LEO satellites. The GEE maximization problem is formulated by taking the inter-beam, inter-carrier, and terrestrial network interference into account. To ease the complexity of the problem, we further simplify the expressions of the GEE and interference and then propose a successive convex approximation (SCA)-based spot beam power optimization method. Numerical results validate its effectiveness over baseline algorithms in different system setups. © 2025, Korean Institute of Communications and Information Sciences. All rights reserved. 2025-10-31T15:00:00Z