用于物联网双频段低功耗CMOS低噪声放大器设计

设计一种用于物联网双频段的低功耗CMOS低噪声放大器(LNA).为了满足双频段和高增益,设计使用共源共栅(Cascode)结构并利用TSMC 0.18um工艺库进行仿真分析.仿真结果表明,在780MHz和433MHz中心频率下,电路的S11均小于-20dB和S21均大于20dB,并且具有好的稳定性.     

童鞋客观舒适性因素的探讨

童鞋舒适性的含义很广,通常可分为主观上的舒适性和客观上的舒适性。上期作者对童鞋主观舒适性因素——包括色彩舒适性、图案舒适性、肌理舒适性、形态舒适性、装饰工艺舒适性和装饰配件舒适性等进行了分析和探讨,本期着重对童鞋客观舒适性因素进行分析探讨。     

树状分支传热结构层次生长优化设计技术

To design heat transfer structures for high heat flux electronic components with small space, reasonable heat transfer channel layout was the most effective approach. Aiming at the complex geometry boundaries and difficult-to-manufacture for heat transfer structures designed by topology optimization, a hierarchy growth method for optimal design of branching heat transfer structure inspired by hierarchical characteristics of natural vein branching system was suggested. Different growth control criteria were adopted for principal channels and lateral channels, which grew in succession to form heat transfer structures. Specifically, space colonization algorithm with temperature information was applied to the growth of principal channels, and the law of minimal thermal resistance was applied to control the growth of lateral channels. Several typical 2D or 3D design problems were studied by the suggested method, and the design results were compared with those of SIMP method. The results show that the heat transfer structure by hierarchy growth method has simple and clear geometry boundary, no tiny channel and gray element, therefore it is easy to be manufactured, and has good thermal performance.     

童鞋主观舒适性因素的探讨

儿童处于客观、主观和认知成长发育时期，受外界影响很大，儿童对自己的用品有着特殊的审美和实用功能要求，所以童鞋作为儿童生活中的必需品，肩负着培养儿童的审美意识、审美能力，促进儿童客观、主观和智力等多方面发展的使命，其中童鞋的舒适性对儿童的健康成长无疑有着重要的影响。     

用小波变换提取高压变压器局部放电脉冲的研究

研究用小波变换提取高压变压器局部放电脉冲。针对载波通讯等缓变干扰，提出了三种基于小波变换的放电脉冲提取方法：二次小波变换法，小波反变换法和小波包变换法，并用仿真实验验证了三种提取方法的有效性，还给出了衡量提取方法有效性的几个概念。     

层次脉状结构液冷均温板优化设计研究

由于耐热型植物具有良好的传热传质能力,结合流道拓扑优化设计和耐热型植物高级脉序的叶脉结构特征,提出一种层次脉状结构液冷均温板的设计方法。以热交换最大和流阻最小为目标开展主流道拓扑优化设计,提取胡杨叶高级脉序的结构特征,形成液冷均温板的次流道。定义结构像素密度作为描述次流道中孔的密度参数,分析其对层次脉状结构液冷均温板的传热传质性能的影响。研究结果表明,层次脉状结构的液冷流道具有较小的流阻和良好的均温性,同时主、次流道尺寸存在最优匹配。进一步研究胡杨叶脉的分布规律,发现液冷板主、次流道尺寸最优匹配规律与胡杨叶低、高级脉序尺寸匹配规律相近。研究结果不仅为液冷均温板的设计提供新思路,而且验证了耐热植物叶脉结构特征对其传热传质性能产生的正面影响。最后加工液冷板,通过试验验证了设计方法的有效性及数值模拟的准确性。     

用于无线传感网络低功耗亚阈值CMOS低噪声放大器设计

设计一种工作在亚阈值区的低功耗CMOS低噪声放大器(LNA),用于无线传感网络.为了满足低功耗和高增益,设计使用共源共栅(cascode)结构并利用UMC 65nm工艺库进行仿真分析.仿真结果表明,在780MHz中心频率下,电路的增益大约34 dB,功耗仅为55μW,电源电压为1.2V.