Baseband signal predistortion based compensation technique for broadband I/Q modulation impairments in vector signal generators

I/Q modulation impairments compensation is an essential part of vector signal generation. In this paper, a novel compensation method based on baseband signal predistortion is proposed to broadband vector modulation. The causes of vector modulation errors via I/Q impairments are analysed numerically. Then a mathematic model of the modulation errors is given, and a compensation method is developed with this model. The model parameter identification process is also elaborated. In addition, the operation process of the proposed method in broadband case is described. Finally, an actual experiment result is provided to test the validity..