摘要
以C8051F040高性能单片机、AD9850和Altera Cyclone EP1C3T144 FPGA为核心,由控制模块、信号产生模块、放大模块、调制模块、键盘及LCD显示等模块组成的系统,实现了频率范围为20 Hz^20 MHz、步进为10 Hz,电压峰-峰值为6Vopp的正弦波信号输出;用FPGA产生的1 kHz的调制信号控制AD603放大器增益实现模拟幅度调制(AM)信号输出;根据调制信号幅度改变AD9850频率控制字实现模拟频率调制(FM)信号输出;用FPGA实现了2ASK和2PSK数字调制信号输出.
The core of this system is composed by high performance microcontroller C8051F040, AD9850 and Ahera Cyclone EP1C3T144 FPGA, including control module, signal generating module, amplifying module, modulating module, keyboard, LCD and so on. Sine signal can be generated by this system. The which frequency range is 20 Hz-20 MHz, step is 10Hz and peak to peak voltage is 6 Vopp. Signal output of simulation amplitude modulation （AM） is realized by the amplifier AD603, whose gain is controlled by lkHz modulating signal which generated by FPGA. According to the amplitude of modulating signal, the frequency control word of AD9850 can be changed. Consequently, the signal output of simulalion frequency modulation （FM） is realized. Output of 2 ASK and 2 PSK digital modulation signal is realized by FPGA.
关键词
单片机
信号发生器
调制
频率
microcontroller
signal generator
modulation
frequency
