高速D/A转换器的WCDMA ACLR测试技术研究

Study on WCDMA ACLR Testing Technology for High Speed D/A Converter

D/A转换器是数字通信系统中的关键器件,其性能直接决定了发射通道的指标参数。随着D/A转换器转换速率的不断提高以及功能的不断增强,传统的混频器、调制器以及放大器等RF后端电路已逐渐被GS/s级超高速RF D/A转换器所取代。由于上述RF器件3阶交调失真(IM3)引起的相邻信道泄露逐渐开始转移至高速D/A转换器上,ACLR成为通信系统的关键技术指标。分析了D/A转换器WCDMA ACLR测试激励信号的关键技术,提出了D/A转换器WCDMA ACLR测试激励信号的产生算法,并采用MATLAB对整个流程进行了仿真。仿真及实测结果表明,该方法是有效和可行的。

As the critical part of digital communication system, the ACLR of D/A converter directly determined the final performance of transmitting channel. With the D/A converter＇s farther development in transmitting rate and functions, traditional RF post end circuits such as mixer, modulator and amplifier was replaced gradually by the GS/s ultra high speed RF D/A converter. The ACLR derived from IM3 of RF circuits above, as important performance of communication system, was gradually shifting to high speed D/A converter. The critical technology of D/A converter WCDMA ACLR testing stimulus signal was analyzed. A method to generate the D/A converter WCDMA ACLR testing stimulus signal was put forward. The whole procedures were simulated by MATLAB. The simulation results and actual testing results both showed that the algorithm was effective and feasible.