用于全数字发射机的数字上变频电路

通过分析数字上变频器系统的工作过程及其主要参数对输出信噪比的影响,合理设计差分电压、预加重电路和高速串行发送器等的布局,有效提高数字上变频电路的性能.实际仿真和硬件测试表明,所设计的数字上变频器可将基带信号直接上变频到907.2 MHz频率上,实现阻带衰减达35 d B,提高了发射端信号的有效性和准确性,可以满足全数字发射机的应用要求.

Digital up-converter circuit for all-digital transmitter

The digital up-converter is a key component of all-digital transmitter, which implements up-convert the base band signal to higher intermediate frequency, including interpolation filters, Delta-Sigma modulators, word generator and high-speed serial transmitter. By means of analysing the system working principle and the effect of principal parameters on the output of signal to noise ratio, and reasonable designing differential voltage, pre-emphasis circuit and high-speed serial transmitter etc, improving the performance of digital up-converter circuit effectively. The actual simulation and hardware test show that, the digital up-converter designed in this paper achieves the function, that is, up-convert the base band signal to the frequency of 907.2MHz, with stop-band attenuation to 35dB, also, increase effectiveness and accuracy of the signal of transmitter, which can meet the application requirement of all-digital transmitter.