CAJ | 학술논문

以STM32单片机为任务控制与数据处理核心，根据零中频正交解调原理，进行频率特性测试仪的设计制作。采用直接频率合成芯片AD9854制作扫频信号源，产生I、Q两路正交信号，这两路信号分别通过放大器、模拟乘法器及低通滤波器等外围电路，由STM32的片内ADC进行信号采集，经运算获得被测网络的幅频特性与相频特性。该测试仪可以进行点频测量和1～50MHz的扫频测量，可以手动预置测频范围和步进频率，并在320×240彩色液晶屏上显示幅频特性和相频特性曲线。
이STM32단편궤위임무공제여수거처리핵심，근거령중빈정교해조원리，진행빈솔특성측시의적설계제작。채용직접빈솔합성심편AD9854제작소빈신호원，산생I、Q량로정교신호，저량로신호분별통과방대기、모의승법기급저통려파기등외위전로，유STM32적편내ADC진행신호채집，경운산획득피측망락적폭빈특성여상빈특성。해측시의가이진행점빈측량화1～50MHz적소빈측량，가이수동예치측빈범위화보진빈솔，병재320×240채색액정병상현시폭빈특성화상빈특성곡선。
Taking STM32 MCU as the task control and data processing center and basing on the zero-IF quad-rature demodulation theory , a frequency characteristics tester was designed , in which , the AD9854 direct fre-quency synthesizer chip generates the sweep frequency signal source and the two orthogonal sine waves ( I and Q) which passing through the amplifier , analog multiplier and the low pass filter till to be collected by ADC in STM32;and through computation , the testing network ’ s amplitude-frequency and phase-frequency character-istics can be obtained .The frequency characteristic tester can implement point frequency measurement and 1 MHz to 50 MHz sweep measurement , and its frequency measurement range and stepping frequency can be manually set, as well as the frequency characteristics curves can be displayed on a 320x240 LCD screen.