本设计采用AT89552单片机，辅以必要的模拟电路，实现了一个基于直接数字频率合成技术(DDS)的正弦谊号发生器。设计中采用DDS芯片AD9850产生频率1KHZ~10MHZ范围内正弦波，采用功放AD811控制输出电压幅度， 由单片机AT89S52控制调节步进频率1HZ。在此基础上，用模拟乘法器MC1496实现了正弦调制信号频率为1KHZ的模拟相度调制信号；用FPGA芯片产生二进制NRZ码,与AD9850结合实现相移键控PSK、幅移键控ASK、频移镇键FSK。-AT89552 the single-chip design, supplemented by the necessary analog circuits, based on the realization of a direct digital frequency synthesis (DDS) generator of sinusoidal No. Friends. The design of DDS chip AD9850 produced using 1KHZ ~ 10MHZ frequency range of sine wave, the AD811 control amplifier output voltage range of from single-chip AT89S52-conditioning step frequency control 1HZ. On this basis, the use of analog multiplier MC1496 has sinusoidal frequency modulation signal 1KHZ degree analog phase modulated signal　generated by FPGA chip NRZ binary code, combined with the AD9850 to achieve phase shift keying PSK, ASK ASK, frequency Shift key town of FSK.