CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Jiancheng Sun,Chi Zhang,Rubing Zhang
Conventional rigid patch antennas, constrained by high-permittivity substrates ( ε r > 3.0) with severe dielectric loss ( tanδ > 0.02), suffer from catastrophic performance degradation at elevated frequencies (>3 GHz) and inherent inflexibility that fundamentally prohibits their integration in wearable electronics. This work presents a breakthrough in synthesizing PMMA-reinforced polyimide aerogels (PIAs) via a 10-min ambient pressure drying (APD) strategy, enabling tunable porosity (>90%) and ultra-low dielectric constants ( ε r = 1.35, tanδ < 0.01). The incorporation of PMMA into the PI matrix endows the aerogel skeleton with outstanding mechanical resilience (tensile strength of 7.2 MPa and fracture energy of 45.8 kJ/m 2 ), while effectively suppressing capillary-induced shrinkage to below 2.1% during solvent evaporation. The synergistic interplay between PMMA encapsulation and APD-optimized solvent exchange yields a hierarchical nanoporous structure (30 nm average pore size) with exceptional thermal insulation (0.036 W/m·K). When deployed as a substrate for flexible Sub-6 GHz patch antennas, the aerogel exhibits 106% gain enhancement (9.92 dBi) and broad impedance bandwidth (3.862–3.941 GHz), outperforming conventional FR-4 substrates. This work establishes a scalable, low-cost paradigm for multifunctional aerogels in wearable electronics and high-frequency communication systems.
研究领域:
材料科学
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电气工程
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纳米技术
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高分子科学
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通信系统
·
柔性电子
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 27
·21737-21745
·
IF 2.779
Lin Feng Li,Liu Bing,Song Kai Xin
NaLaMgWO 6 microwave dielectric ceramics have been synthesized via the standard solid-state reaction method. The Rietveld refinement of the X-ray diffraction patterns indicates that NaLaMgWO 6 crystallizes in a monoclinic crystal structure with a C 2/ m space group. Raman spectrum of the NaLaMgWO 6 ceramic is collected, and the correlations between the Raman active modes and chemical bond vibrations are systematically identified. The optimum microwave dielectric properties are obtained when sintered at 1550 °C, with ε r = 17.1, Q f = 26,150 GHz, and τ f = − 83.4 ppm/°C. A microstrip patch antenna operating at the sub-6 GHz band is fabricated using the NaLaMgWO 6 ceramic as the substrate. The fabricated antenna resonates at 3.82 GHz, which exhibits an excellent S 11 value of − 26 dB, a minimum VSWR value of 1.07, and a satisfactory simulated efficiency of 72.2%. The good antenna performance demonstrates the great application potential of NaLaMgWO 6 ceramic in the sub-6 GHz band antennas.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Bing Liu,Ke Sha,Meng Fei Zhou,Kai Xin Song,Yu Hui Huang,Cheng Chao Hu
Two novel low- ε r gallates MGa 2 O 4 (M = Ca, Sr) have been synthesized via a standard solid-state reaction method. According to the X-ray diffraction results, CaGa 2 O 4 crystallizes in space group Pna2 1 with an orthorhombic symmetry, while SrGa 2 O 4 belongs to the monoclinic P2 1 / c system. Both ceramics show ever-improving microstructures with the increasing sintering temperature . The optimal microwave dielectric properties ( ε r = 9.2, Qf = 66,000 GHz, τ f =–85 ppm/°C for SrGa 2 O 4 and ε r = 10.6, Qf = 15,400 GHz, τ f =–58 ppm/°C for CaGa 2 O 4 ) are obtained when sintered at 1275 °C. A patch antenna is fabricated using SrGa 2 O 4 ceramics as the substrate, which realizes a return loss of –19.94 dB and total efficiency of –1.38 dB (72.8 % in power ratio) at 4.84 GHz. The exceptional performances indicate that SrGa 2 O 4 ceramics are promising candidates for antenna applications at the Sub-6 GHz band.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 2
·704-718
·
IF 3.9
Jian Bao,Wei Du,Haitao Wu,Zhenxing Yue
In this study, two novel microwave dielectric ceramics were designed and synthesized using the solid-state reaction method based on the CaO–MoO 3 –La 2 O 3 pseudo-ternary phase diagram. The X-ray diffraction (XRD) patterns and Rietveld refinement results indicate that pure phase microwave dielectric ceramics (CaLa 2 (MoO 4 ) 4 and Ca 3 MoO 6 ) can be produced with CaO, MoO 3 , La 2 O 3 ratios of 1, 1, 4, and 3, 1, 0, respectively. CaLa 2 (MoO 4 ) 4 shows the potential value for application in Low Temperature Co-fired Ceramic technology. In addition, the Phillips–van Vechten–Levine theory, infrared reflectance spectrum, and THz time-domain spectrum are used further to study the structure-property relationship of the two ceramics. Finally, a 5G patch antenna used in Sub-6 GHz communication technology was successfully designed and manufactured. The study of the relationship between chemical bonds and dielectric properties of the two ceramics, along with the development of the patch antenna, establishes a foundation for scientific research and practical applications in related ceramic systems.
研究领域:
材料科学
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陶瓷
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电磁工程
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电信
✓ 已验证
DOI
高影响因子
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