摘要
在微带贴片天线的基础上，设计了一种介质基板尺寸为34．2mm×34．2mm×1．6mm，材料是FR4（相对介电常数为4．4）的简易差分微带天线，并基于传输线理论给出了差分天线输入阻抗与馈电点间的关系。用软件HFSS对天线进行仿真分析，结果表明：天线工作带宽为2．41～2．47GHz（回波损耗）≤-10dB），适用于无线局域网WLAN802．11b（2．4-2．48GHz）系统，在工作频段内具有良好的辐射方向性。差分天线把差分信号直接馈入到天线的两个端口，为设计高集成的射频前端提供了新途径。
The presser foot of existing computerized embroidery machine collides with other parts when working.To solve the problem,firstly we analyzed the working principle of the presser foot of computer embroidery machine,and found the reason for collision.Then,based on complex-number vector method and the software of Matlab,operating law of the presser foot was obtained.The design improvements of drive presser foot by using disc groove cam and swinging block mechanism was put forward on the premise of keeping the operating law of presser foot unchanged.Then we got the profile curve of the cam by using analytical method based on the principle of reverse.The improved design of drive presser foot eliminates the collision of head presser foot and other parts,reduces the rack vibration,and satisfies the high-speed technical requirements.
出处
《浙江理工大学学报（自然科学版）》
2016年第3期398-402,共5页
Journal of Zhejiang Sci-Tech University(Natural Sciences)
基金
国家自然科学基金项目(61101052)
浙江省教厅科研项目(Y201329492)
关键词
反射损耗
差分
奇模反射系数
HFSS
微带天线
computerized embroidery machine
heads of computerized embroidery machine
presser foot
driving mechanism
design improvements
cam
