CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chang Jiang,Longxiang Jiang,Qianbiao Du,Linzhao Ma,Zhicong Chen,Hao Li
LiMg 6 GaO 8 ceramics were synthesized via solid-state reaction method. Systematic investigation reveals that samples sintered at 1260 °C demonstrate exceptional microwave dielectric properties (MDPs): ε r = 10.82, Q×f = 123,083 GHz, and τ f = −22.76 ppm/°C. P-V-L theory analysis indicates that Mg-O bonds dominate lattice energy (72.6 %), while Ga-O bonds contribute most to ionicity (35.7 %). Based on these excellent MDPs, the designed array dielectric resonator antenna (DRA) achieves significant gain and radiation efficiency. The unit DRA delivers performance with 5.78 dBi gain and more than 90 % radiation efficiency. Its breakthrough two-element array DRA boosts gain to 6.39 dBi, providing an improvement over conventional designs while maintaining high radiation efficiency.
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
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Yanan Wang,Chengzhuang Su,Songru Wang,Hao Tang,Hailuo Liu,Dong Wang,Aimin Wu,Hao Huang
The high integration of electronic devices severely hinders heat dissipation, impacting intelligent system performance. This study fabricated Cr-incorporated amorphous carbon films on aluminum alloy heat sinks using pulsed bias arc ion plating to enhance thermal performance. Film morphology and composition were analyzed via transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Cr content was precisely regulated by adjusting the Cr target current, which was set at 0 A, 20 A, 40 A, and 60 A, respectively, and the effect of the sp 2 /sp 3 hybridization ratio on thermal dissipation was investigated. Results showed that increased Cr content led to the formation of B1-CrC in the amorphous carbon matrix. Optimal thermal performance occurred at a Cr target current of 20 A, at which the Cr content reached 6.21 at.%, yielding an infrared emissivity of 0.67 and a thermal conductivity of 160.95 W·m −1 ·K −1 . LED lamps coated with the Cr/C film exhibited a surface temperature 9.7 °C lower than that of uncoated lamps, thereby demonstrating excellent heat dissipation. The study underscores the synergistic effect of radial thermal conductivity and infrared emissivity in improving heat sink efficiency under non-forced convection.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Electronic Materials
·
2022
·Vol. 8
·期 9
·2101414
·
IF 7.633
Chao Du,Di Zhou,Rui-Tao Li,He-Tuo Chen,Guo-Hong Zhou,Bin Tang,Moustafa Adel Darwish,Song Xia,Zhuo Xu
In this paper, the medium dielectric constant 0.65CaTiO 3 -0.35LaAlO 3 (CTLA) composite microwave ceramic is employed to introduce in dielectric patch antennas (DPA). Typical, high-performance microwave dielectric properties of ε r ≈ 44.8, Q × f ≈ 43 950 GHz@3.67 GHz and TCF ≈ 0 ppm °C –1 can be obtained by solid-state reaction method in CTLA composite microwave ceramics sintered at 1450 °C for 2 h. Then, the CTLA composite ceramic patch fired with silver coating is mounted on the Rogers RO4003C substrate operating as a magnetic wall boundary. A simplified cavity-like theoretical model is used to analyze the proposed DPA structure and the accuracy of this antenna model is evaluated by the theoretical results from a commercial CST Microwave Studio 2019. Based on this, the CTLA composite ceramic physical property is modified to enhance the radiation efficiency and reduce profile of the DPA. The higher-order TM 121 mode is brought close to the dominant TM 101 mode by taking advantage of the multimode characteristics of the dielectric patch resonator and introducing a sintered silver slot in the ceramic dielectric patch. For demonstration, the proposed DPA prototype operating in the multiprobe antenna near the field measurement system is implemented and measured.
研究领域:
电子工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Technologies
·
2023
·Vol. 8
·期 10
·2201985
·
IF 6.8
Chao Du,Xiang-Kun Li,Di Zhou,Shao-Fei Wang,Rui-Tao Li,Xiao-Gang Yao,Hui-Xing Lin,Hai-Yi Peng,Tao Zhou,Shi-Kuan Sun,Song Xia,Zhuo Xu
Array antenna is of great significance in realizing the Sub-6 GHz fifth-generation (5G) mobile communication systems, however, its utilization in the base station systems implementation is limited due to high power consumption. In this paper, a high radiation efficiency 4 × 4 cylindrical dielectric resonator antenna (CDRA) array fabricated using the temperature stable 0.8Zn 2 SiO 4 -0.2TiO 2 composite ceramic is proposed. TiO 2 -doped Zn 2 SiO 4 composite ceramics are synthesized by the conventional solid-state method. Notably, 0.8Zn 2 SiO 4 -0.2TiO 2 composite ceramic sintered at 1250 °C demonstrates excellent microwave dielectric properties with dielectric constant (ε r ≈ 8.24), high-quality factor ( Q × f ≈ 35 000@8.08GHz), and the temperature coefficient of resonant frequency ( TCF ≈ +4.6 ppm °C −1 ). Moreover, the composite ceramic CDRA array is designed by exciting fundamental HE 11δ mode using the aperture coupling microstrip feeding network. The fabricated composite ceramic based 4 × 4 CDRA array has enhanced measured radiation efficiency of up to 87%, high gain of 17.85 dBi and is a promising candidate for utilization in Sub-6 GHz 5G Base Station communications systems.
研究领域:
通信工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Tingting Tang,Hua Huang,Chaoyang Li,Jian Shen
High performance and miniaturization are becoming increasingly important for practical microwave electronics and high-density communication systems. Here, LiNb 0.6 Ti 0.5- x (Zn 1/3 Nb 2/3 ) x O 3 (LNT- x ZN, x = 0, 2, 4, 6, 8 mol%) ceramics have been successfully prepared by a solid-phase reaction. The relationship between the physical structure, microscopic morphology, Raman spectroscopy , and microwave properties is revealed. The better microwave dielectric properties of the LNT-4ZN ceramic sintered at 1075 °C are ε r ∼59.9, Q× f ∼8261 GHz, and τ f ∼-7.4 ppm/°C. Using this ceramic, a miniaturized dielectric resonant antenna (DRA) is designed and demonstrated. The return loss, radiation efficiency, and realized gain of this device at the center frequency are −43.57 dB, 78.4 %, and 8.59 dB, respectively. The antenna, in addition to the good radiation performance, has a size advantage over similar devices (#Cylindrical sample, # R 3.1 mm × h 1.6 mm, @Square substrate, @ a = b = 18 mm × h 3.1 mm). This work exemplifies the great potential of LNT-4ZN materials in communication devices and promotes the application of microwave dielectric ceramics in antenna fields.
研究领域:
材料科学
·
电气工程
·
微波技术
·
陶瓷
·
天线设计
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）