Abstract: (140 Views)
Bandpass filters (BPFs) are critical components in 5G radio-frequency front-end systems, where wide bandwidth, low insertion loss, and compact size are simultaneously required. In this paper, a metamaterial-inspired wideband BPF based on Complementary Split Ring Resonators (CSRRs) loaded with a dumbbell-shaped Defected Ground Structure (DGS) is proposed for mid-band 5G applications centered at 4.7 GHz. Unlike conventional designs that rely on commercial electromagnetic solvers, the proposed filter is developed and analyzed using a fully open-source electromagnetic simulation framework based on Open EMS, enabling cost-effectiveness and design reproducibility. The design evolution from a single-ring CSRR to a triple-ring configuration is systematically presented to enhance magnetic coupling and bandwidth. The incorporation of a dumbbell-shaped DGS further modifies the ground current distribution, leading to improved selectivity and reduced insertion loss. The optimized filter achieves a fractional bandwidth of approximately 43%, a minimum insertion loss of 0.72 dB, and a return loss better than -35 dB using a low-cost FR-4 substrate. Comprehensive parametric analysis, metamaterial characterization, group delay response, and electromagnetic field distribution are provided to validate the proposed approach. The results demonstrate that the open-source Open EMS-based methodology can achieve performance comparable to commercial solvers, offering an accessible and reliable design pathway for next-generation microwave filter development.
Type of Study:
Research Paper |
Subject:
Microwave Passive Circuits Received: 2025/11/28 | Revised: 2026/05/10 | Accepted: 2026/02/05