模拟正交调制误差数字校正方法

模拟正交调制可有效降低对FPGA等数字器件的工作频率要求,特别适合于高等级大规模高速FPGA器件受到限制的星载设备及军用设备研制场合。但由于器件指标限制及电路的不一致性,模拟正交调制存在较大的电路误差,而通过电路设计和调试将误差减小的工程实现难度较大。提出一种数字校正方法,通过在基带信号引入2个校正因子,可有效校正模拟正交调制的电路误差,完全满足正交不平衡度小于1°、幅度不平衡度小于0.2dB的指标需求。

The Error Correction Method of Analog Quadrature Modulation Based on Digital Predistortion

Analog quadrature modulation can effectively reduce the demand of work speed of dig-ital devices, so it is especially suitable for satellite equipment and military equipment develop-ment while high grade, large-scale, high speed logic devices is embargoed. However, because of the defects of components and circuits, analog quadrature modulation may bring on serious signal distortion, and it is usually very difficult to deal with this problem by designing and de-bugging. A new method is presented, by introducing two correction factors into the baseband signal, which can effectively revise the error of analog quadrature modulation, fully meet the de-mands of quadrature unbalanced less than 1 degree, and amplitude imbalance less than 0. 2dB.