蜂窝电话功率放大器-天线接口的自适应调谐

本文分析了目前无线产品设计面临的挑战，提出了一种只需少量电路，占用较少电路板面积的解决方案，即将功率放大器和前端模块RF装置集成到天线结构的蜂窝无线电天线模块中，针对天线负载条件使天线和RF电路实现最佳匹配。     

Flow Characteristics and Dynamic Behavior of Polyamide 6/Acrylonitile Butadiene Styrene (PA6/ABS) Blends

The objective of this research was to investigate the effect of incorporation of maleic anhydride grafted acrylonitrile-butadiene-styrene (ABS-g-MAH) on rheological properties of PA6/ABS blends. Flow properties of the blends were examined by dynamic and capillary rheometers. The dynamic rheological analyses showed an increase in complex viscosity with the incorporation of a compatibilizer. The reduction of tan δ peaks showed enhanced interfacial interaction between PA6 and ABS phase, which resulted in the enhancement of melt strength. The power law index analysis showed that 1.5 wt.% resulted in minimum n and maximum K value for the blends while still retaining the pseudoplastics behavior necessary for plastics processing and prediction for the end use performance of the PA6/ABS blends.     

高压运算放大器PA69在MEMS光栅驱动控制中的应用

根据MEMS光栅的工作特点及结构参数,提取光栅的等效电容,并采用高压运算放大器PA69研制出一种新型的MEMS光栅的动态驱动电路.为了避免自激振荡的发生,电路中采用了频率补偿和并联反馈电容的方法,有效提高了电路的稳定性.经过测试,其动态性能与PSPICE10仿真的结果非常吻合.该动态驱动电路完全能够满足MEMS光栅动态复杂控制的需要.     

Dirty RF: A New Paradigm

The implementation challenge for new low-cost low-power wireless modem transceivers has continuously been growing with increased modem performance, bandwidth, and carrier frequency. Up to now we have been designing transceivers in a way that we are able to keep the analog (RF) problem domain widely separated from the digital signal processing design. However, with today’s deep sub-micron technology, analog impairments – “dirt effects” – are reaching a new problem level which requires a paradigm shift in the design of transceivers. Examples of these impairments are phase noise, non-linearities, I/Q imbalance, ADC impairments, etc. In the world of “Dirty RF” we assume to design digital signal processing such that we can cope with a new level of impairments, allowing lee-way in the requirements set on future RF sub-systems. This paper gives an overview of the topic and presents analytical evaluations of the performance losses due to RF impairments as well as algorithms that allow to live with imperfect RF by compensating the resulting error effects using digital baseband processing.     

高精度数字跟踪式压电陶瓷驱动电源设计

设计了一种数字跟踪式复合结构的压电陶瓷驱动电源。采用数字式自适应信号源,驱动高精度运放OP07和高压大电流运放PA04组成复合式放大器,通过合理的相位补偿、保护电路设计和散热计算,实现高精度低漂移的压电陶瓷驱动。     

PA1688双核处理器的电视播放故障监控系统设计

针对数字电视故障监控中常出现的间距,提出一个采用低成本的双核（MCS51＋DSP）处理器的解决方案,并给出软硬件设计方法。该方案不但能对文中提出的几类故障进行监控,而且经过软件升级后,能对大部分的故障进行监控和处理,满足数字电视发展过程中日益增长的需求。     

超临界N_2微孔发泡PA6的制备及性能研究

采用超临界N2微孔发泡注射成型方法制备微孔发泡尼龙(PA)6材料,研究了注射温度、成核剂含量对泡孔密度、直径的影响。采用扫描电子显微镜考察了注射温度对泡孔大小、密度以及分布的影响。结果表明,随着注射温度的升高,泡孔直径变大,泡孔密度减小;成核剂含量增加泡孔密度变大,成核剂到达一定含量后泡孔密度增大不显著,成核剂含量对泡孔直径无显著影响。     

压缩和回复下PA6/MWCNTs/SSFs复合材料导电性研究

通过熔融共混、注射成型将多壁碳纳米管(MWCNTs)和不锈钢纤维(SSFs)与尼龙(PA)6复合制成PA6/MWCNTs/SSFs导电复合材料,在万能试验机上对其进行单轴压缩蠕变和阶梯回复实验,对材料的电阻率、应力、应变进行同步测量,研究不同应力及SSFs含量下复合材料的电阻率变化。结果表明,该复合材料在阶梯应力加载瞬间发生普弹形变,维持恒定应力后,发生高弹形变和粘流形变,阶梯应力卸载后,应变会有所回复。压缩蠕变状态下,当应力为10,20 MPa时,加载瞬间复合材料电阻率会发生突变下降;当应力维持在10 MPa时,电阻率随应变的增加呈下降趋势,即发生电阻蠕变现象,SSFs质量分数为10%的复合材料电阻蠕变现象最为明显;随着应力水平增大,电阻蠕变现象消失,电阻率趋于稳定,但当SSFs质量分数为8%时,电阻率存在较大波动;阶梯回复状态下,复合材料电阻率基本稳定,但当应力卸载到10 MPa时,电阻率存在波动,随着SSFs含量增加,波动趋于平缓。根据Burgers蠕变模型以及聚合物荷载响应特点,认为这主要是由于聚合物分子链的运动对导电通路的影响引起的。     

混杂纤维增强PA66复合材料扶正器的研究

采用注塑工艺制备了碳纤维(CF)/玻璃纤维(GF)混杂增强尼龙66(PA66)复合材料,并在模拟高含水及高腐蚀两种井况下分别进行摩擦磨损、线胀系数对比和冲击试验,最终筛选了15%CF/20%GF和20%CF/20%GF两种混杂纤维增强PA66,制成了新型油井用扶正器,利用扫描电子显微镜对材料的磨擦表面及冲击断口进行了观察与分析。结果表明,在高含水的稀油井中,适合使用15%CF/20%GF增强PA66扶正器;在高含水的稠油井中,由于井下温度较高,20%CF/20%GF增强PA66扶正器与15%CF/20%GF增强PA66扶正器相比,尺寸稳定性更好,耐磨性更高,因此适合该类油井。     

PA6/BIIR动态硫化合金的制备、性能与应用

利用动态硫化法制备尼龙(PA)6/溴化丁基橡胶(BⅡR)合金,通过对其拉伸强度、冲击强度及熔体流动速率(MFR)等性能进行测试,讨论了马来酸酐(MAH)对合金力学性能和流动性能的影响,通过扫描电子显微镜观察合金冲击断面的形貌。结果表明,当MAH的含量为0.5份时,合金的力学性能和流动性能最好,此时的拉伸强度为19.8 MPa,断裂伸长率为15%,缺口冲击强度为26.1 kJ/m2,MFR为0.15 g/(10 min)。该合金可以作为阻气材料的衬里使用。