《电子技术应用》
您所在的位置:快乐赛车 > 其他 > 设计应用 > 晶体三极管开关混频电路研究
晶体三极管开关混频电路研究
2020年电子技术应用第9期
张宏强,王 勇,刘乃安
西安电子科技大学 通信工程学院,陕西 西安710071
摘要: 针对传统的乘法器混频方式受本振信号影响,且存在很多干扰和失真,很大程度影响接收机的性能,采用晶体三极管开关混频方法解决这一问题。详细推导了开关混频的数学公式,通过对方波信号进行傅里叶级数展开,提出了I型、II型开关混频的数学模型,并针对NPN三极管开关电路提出设计方案。在Multisim软件环境中实施了仿真验证,以AM信号为例进行三极管开关混频,引入加速电容消除了电路的负峰切削失真,并滤出中频信号,仿真结果较为理想。理论和实践表明,基于晶体三极管开关的混频方式避免了本振信号的干扰,可提高接收机性能。
中图分类号: TN710.2
文献标识码: A
DOI:10.16157/j.issn.0258-7998.200240
中文引用格式: 张宏强,王勇,刘乃安. 晶体三极管开关混频电路研究[J].电子技术应用,2020,46(9):127-131,136.
英文引用格式: Zhang Hongqiang,Wang Yong,Liu Naian. Research on BJT switch mixing circuit[J]. Application of Electronic Technique,2020,46(9):127-131,136.
Research on BJT switch mixing circuit
Zhang Hongqiang,Wang Yong,Liu Naian
School of Telecommunications Engineering,Xidian University,Xi′an 710126,China
Abstract: In allusion to the problem that traditional multiplier mixing method is affected by local oscillator and there exists interferences and distortions, which greatly affects the performance of receiver, a bipolar junction transistor(BJT) switch mixing method is proposed. The mathematical formula of switch mixing is deduced in detail, and two mathematical models, I-type and II-type switch mixing models are proposed by using Fourier series expansion of square wave. Based on NPN BJT switch, a mixing circuit is designed, and simulation is carried out on Multisim software environment. AM signal is used as an example to mix on BJT switch. Acceleration capacitor is added to eliminate negative peak cutting distortion and intermediate frequency signal is filtered out. The results of simulation are ideal. It is proved theoretically and practically that BJT switch mixing method prevents the interference of local oscillator signal, which can enhance receiver performance.
Key words : bipolar junction transistor;mixing;local oscillator signal;Fourier series;acceleration capacitor

0 引言

    混频一般通过非线性元件或者专用的集成电路乘法器来实现,混频信号的幅度和相位信息受本振信号影响,并且也会引入很多干扰和失真,这些都会降低接收机的性能[1]。开关混频方式可解决以上问题,且晶体三极管廉价易得,开关电路易于实现,原理如图1所示。




本文详细内容请下载:http://www.jganggini.com/resource/share/2000003001




作者信息:

张宏强,王  勇,刘乃安

(西安电子科技大学 通信工程学院,陕西 西安710071)

此内容为AET网站原创,未经授权禁止转载。
快乐赛车 欢乐生肖 彩票高賠率好平台 三分PK拾平台 湖南快乐十分走势 秒速时时彩 澳洲幸运8 天津十一选五前三走势 智慧彩票投注 上海时时乐