毕业设计论文--无线智能信号检测仪.docVIP

摘 要 在通信、遥测遥控等无线电系统中，由于受发射功率大小、收发距离远近、电波传播衰落等各种因素的影响，接收机往往很难辨识是信号失真还是干扰信号。本文设计的无线信号智能检测仪可以检测发送信号的功率、频率等各项物理参数。它的几项关键技术包括：自校零与自校准技术、程控放大电路和程控滤波电路的原理和实现途径。它可以实现程控滤波，放大器增益可设置；低通或高通滤波器通带、截止频率等参数可设置。硬件以单片机AT89C52为核心控制，主要由PGA103放大器、程控滤波器MAX262、椭圆滤波器和幅频特性测试（DDS）等部分组成。放大器采用PGA103实现60dB固定增益放大，步进10dB由单片机控制AD7520实现，其误差不大于5%低通、高通滤波器由单片机控制可编程滤波器芯片MAX262实现，在2fc处放大器与滤波器的总电压增益不大于30dB。幅频特性测试由DDS产生信号经峰值检波后送入A/D转换实现。本系统设计简单，使用方便，具有较高的性价比、实用性和使用价值。 关键词：智能检测仪；无线信号；程控滤波器；程控放大器；单片机 Abstract In correspondence, telemetering remote control and so on in radio system, because the emissive power size, receiving and dispatching is away from far and near, the radio wave propagation decline and so on each kind of factor influence, the receiver often the very difficult identification is the signal distortion or the unwanted sinal.This article designs the wireless signal intellingence instrumentation may examine the transmission signal the power,the frequency and so on each physical parameter.Its several keychnologis include:Self-correcting zero and from calibration control technology,program enlgrgement and program control filter circuit principle and realization way.This system can realize the digital programmable filter and also could intercalate the gain of amplifier, the passband parameter and cut-off frequency of LPF or HPF could be intercalated. The hardware uses MCU(AT89C52)as the core to control the system, it consist of the PGA103、MAX262、the four-order elliptic low-pass filter and DDS an so on. The amplifier uses the PGA103, the fixed gain of amplifier is 60dB, the AT89C52 control the AD7520, it could realize the controled 10dB gain, the error has 5%. The LPF and HPF are realized by the programmable switched-capacitor filter integrated chip MAX262, the chip is controled by the AT89C52, the voltage gain of amplifier and filter is 30 dB in the 2fc, DDS theory is adopted to produce Amplitude-frequency. chararcteristics tester Keywords: Intelligent instrumentation; Wireless signal; Program con