Introducing periodic structures into GFRP is a key approach to integrating structural and microwave-absorbing functions. However, conventional metallic periodic structures often cause stress concentration problems. In this study, periodic CIP/CF grid structures were embedded into GFRP laminates, which were made from CIP-modified continuous CF tapes. This design uses epoxy resin for integral molding of continuous GFs and CFs, which can effectively prevent interfacial stress concentration and maintain the excellent mechanical properties of GFRP laminates. Critical geometric parameters, including the CIP/CF grid bandwidth and GFRP layer thickness, were optimized using the genetic algorithm in MATLAB. The optimized structure was then modeled, and its microwave absorption performance was verified using HFSS software. Experimental results confirmed the HFSS simulation data, showing effective absorption in the 6.3–8.8 and 10.3–18 GHz frequency bands, with a peak absorption of −33.8 dB. Additionally, the microwave-absorbing laminate with periodic CIP/CF grid retained the inherent high specific strength of GFRP and exhibited improved flexural strength, reaching 470 MPa (a 7% improvement over neat GFRP). The combined electromagnetic properties of GFRP, CF, and CIP, along with the synergistic effect of the CIP/CF grids, enabled the ultimate laminate to achieve broadband microwave absorption performance.
Zelai Cheng,Xingyu Huo,Zhen Zhao,Feng Qiao,Xiuling Yang,Ying Chen,Mingshan Qu,Hua Su
This work presents a miniaturization strategy for ferrite circulators by enhancing the dielectric constant ε r of NiCuZn ferrites and LTCC technology. Highly polarizable Cu 2+ and Ti 4+ substitutions for Ni 2+ and Fe 3+ increase dielectric constant, while non-magnetic Ti 4+ reduces magnetocrystalline anisotropy and narrows ferromagnetic resonance linewidth ΔH , with Cu 2+ concurrently lowering sintering temperatures. In the Ni 0.42-x/2 Cu 0.18+x Zn 0.4 Ti x/2 Fe 1.98-x O 4-δ system, the x = 0.1 composition (sintered at 975 °C) achieves minimal ΔH (82 Oe), ε r ≈ 14.6, and 4π M s ≈ 4219 G, whereas x = 0.6 (sintered at 925 °C) balances ε r ≈ 20.8 with magnetic performance ( ΔH ≈167 Oe, 4π M s ≈ 2117 G), confirming LTCC compatibility. A heterostructured substrate fabricated by co-firing Ni 0.12 Cu 0.78 Zn 0.4 Ti 0.3 Fe 1.38 O 4-δ ferrite (x = 0.6) with a microwave dielectric (50 wt.% SrCu 0.95 Mn 0.05 Si 4 O 10 + 50 wt.% Sr 3 V 2 O 8 ) exhibits controlled interfacial diffusion. HFSS simulations demonstrate that the integrated circulator-filter achieves significant miniaturization with >30 dB harmonic suppression (14-24 GHz) while maintaining in-band performance (| S 21 | < 1 dB, | S 11 | and | S 12 | < -20 dB at 7-12 GHz). The validates high- ε r NiCuZn ferrites and LTCC composite substrates for compact multifunctional microwave components.
危险品化学品经营许可证（带存储）