超外差式无线电信号接收可视化统调方法研究  

Research on visualization tuning method of superheterodyne radio signal receiving

作　　者：董德礼[1] 许敬 梁阿磊[1] DONG Deli;XU Jing;LIANG Alei(Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学,上海200240

出　　处：《现代电子技术》2022年第22期63-67,共5页Modern Electronics Technique

摘　　要：中频放大的超外差接收电路被广泛应用于现代收音机、电视机、对讲机等无线电接收设备中,其接收电路通常包括三级放大以及谐振、本振、频差、滤波等组成部分。可调节器件如调谐电容及补偿电容、谐振线圈等的非线性特性及多个器件调节的匹配问题,以及使接收电路在从低到高的有效频段上都获得准确的频差值(即中频)以及理想的增益,已成为电路调试的难点。目前常用的调试方法都偏重于经验(如逐步渐近法、三点平衡法等),虽然操作简单、无需仪器,但调试效果有时受制于调试环境(屏蔽、干扰等因素),难以保证调试效果。针对超外差接收电路的调试方法存在的不足,文中提出一种基于数字示波器和频谱分析仪等测量设备的调试方法。该方法通过波形、频谱图可直观地显示信号在调试过程中的变化,对于理解电路参数变化对接收信号处理过程的影响具有较大帮助,对大专院校的电子类实践教学与学习以及无线电专业维修人员都有实际的指导意义。Superheterodyne receiving circuit with intermediate frequency amplification is widely used in modern radios,televisions,walkie-talkies and other radio receiving equipment.The superheterodyne receiving circuit has the function of three-stage amplification,and includes resonance,local oscillator,frequency difference,filtering and other components.The nonlinear characteristics of adjustable devices,such as tuning capacitor,compensation capacitor,resonant coil,etc.,and the matching problem of multiple device adjustments make the circuit debugging of the receiving circuit difficult to obtain accurate frequency difference(i.e.intermediate frequency)and ideal gain in the effective frequency band from low to high.The commonly used debugging methods(such as gradual asymptotic method,three-point balance method,etc.)focus on experience.Although their operations are simple and they don't need any instrument in their operations,their debugging effects are sometimes limited by the debugging environment(shielding,interference,etc.),which is difficult to ensure the debugging effect.In allusion to the deficiency of the debugging method of superheterodyne receiving circuit,a debugging method based on measurement equipment such as digital oscilloscope and spectrum analyzer is proposed.This method can intuitively display the changes of the signal during the debugging process by means of the waveform and spectrogram,which is helpful to understand the impact of circuit parameter changes on the process of receiving signal processing.It also has practical guiding significance for the practical teaching and learning of electronics in universities as well as for radio maintenance personnel.

关 键 词：超外差无线电信号接收 电路调试 信号跟踪 调试过程显示 频谱分析 信号可视化 

分 类 号：TN926-34[电子电信—通信与信息系统]