TiC/PE蜡复合材料在60 GHz波段的微波介电性能研究

Study on the Microwave Dielectric Properties of TiC/PE Wax Composite Materials in the 60 GHz Band

摘要:

随着毫米波技术的快速发展，60 GHz毫米波段在通信、雷达、遥感等领域展现出巨大的应用潜力。然而，60 GHz波段的波长短，在传播过程分布效应明显，信号容易受到干扰。为解决该问题，开发一种高效的毫米波吸波材料具有重要意义。由于TiC具备较好的介电性能、较大的介电损耗值及良好的电磁波吸收特性，因此对TiC粉体及其复合材料在60 GHz毫米波段的微波吸收性能进行了研究。探究TiC粉体填充比例（质量分数）和热处理温度对TiC/PE复合材料复介电常数和微波吸收性能的影响，并通过X射线物相分析仪（XRD）、扫描电子显微镜（SEM）、差示扫描量热仪（DSC）和激光粒度仪（LPS）分别对样品进行表征。实验结果表明，随着TiC粉末质量分数的增加复合材料的复介电常数增大，热处理温度可以调节复合材料的微波吸收性能。当TiC质量分数为75%时，复合材料的复介电常数实部（ε'）为11.19—12.60、复介电常数虚部（ε″）为3.33—3.91，在厚度0.30 mm处最小反射损耗(RL_min)可达-24.20 dB，厚度为0.35 mm时相应的最大有效吸收带宽（EAB）可达 15.50 GHz。当热处理温度为200 ℃时，TiC/PE复合材料的ε'为14.45—16.54、ε″为5.56—6.44，在厚度0.30 mm处RL_min可达-19.18 dB，而EAB可达 16.83 GHz；当热处理温度为325 ℃时，TiC粉末发生氧化开裂，其ε'为10.67—11.05、ε″为0.86—1.19，在厚度2.15 mm 处RL_min可达-48.28 dB，当厚度为1.10 mm时EAB可达5.50 GHz。通过调整TiC粉体的质量分数和热处理温度，可以达到调控复介电常数的目的，使TiC粉末复合材料的EAB保持在较大的频率范围内。TiC粉末复合材料在60 GHz毫米波段表现出良好的微波吸收性能，为毫米波段微波吸收材料的设计提供了重要参考。（专精特新·电磁波吸收与屏蔽用新型材料的研究进展专辑十二之十一）

Abstract:

With the rapid advancement of millimeter-wave technology， the 60 GHz band has demonstrated considerable potential for applications in communications， radar， remote sensing， and various other domains. However， the short wavelength inherent in the 60 GHz band leads to significant propagation distribution effects， rendering signals highly susceptible to interference. To mitigate this challenge， the development of effective millimeter-wave absorbing materials is crucial. Given TiC’s superior dielectric properties， high dielectric loss， and robust electromagnetic wave absorption capabilities， research has focused on the microwave absorption performance of TiC powders and their composites within the 60 GHz band. The study investigated the influence of TiC powder filling ratio （mass fraction） and heat treatment temperature on the complex permittivity and microwave absorption performance of TiC/PE composites. Characterization of the samples was conducted using X-ray diffraction （XRD）， scanning electron microscopy （SEM）， differential scanning calorimetry （DSC）， and a laser particle size analyzer （LPS）. Experimental results indicate that an increase in TiC powder mass fraction results in an elevation of the composites' complex permittivity， with microwave absorption performance adjustable via heat treatment temperature. Specifically， at a TiC mass fraction of 75%， the real part （ε'） of the complex permittivity ranged from 11.19 to 12.60， the imaginary part （ε″） from 3.33 to 3.91， achieving a minimum reflection loss （RL_min） of -24.20 dB at a thickness of 0.30 mm， and a maximum effective absorption bandwidth （EAB） of 15.50 GHz at 0.35 mm thickness. When the heat treatment temperature was set to 200 ℃， ε' ranged from 14.45 to 16.54， ε″ from 5.56 to 6.44， with RLmin reaching -19.18 dB at 0.30 mm thickness and an EAB of 16.83 GHz. Conversely， at 325 ℃， TiC powder underwent oxidation and cracking， resulting in ε' values between 10.67 and 11.05， ε″ between 0.86 and 1.19， RL_min of -48.28 dB at 2.15 mm thickness， and an EAB of 5.50 GHz at 1.10 mm thickness. By manipulating the TiC powder mass fraction and heat treatment temperature， the complex permittivity can be controlled， enabling the maintenance of a large EAB for TiC powder composites across a broad frequency range. TiC powder composites exhibit outstanding microwave absorption performance in the 60 GHz band， offering valuable insights for the design of microwave absorbing materials in the millimeter-wave spectrum.