A Magnitude-Response Compensation Method in the FI-DAC-Based Arbitrary Waveform Generator

An arbitrary waveform generator (A WG) is a general-purpose testing device that can easily generate excitation signals according to user needs. With the continuous evolution of electronic science and technology, increasing demands for a higher AWG sampling rate and output bandwidth has been put forward. A frequency-interleaved digital-to-analog converter (FI-DAC) can improve those parameters quite effectively. However, due to the magnitude roll-off characteristic of the DAC and the magnitude attenuation of analog devices, such as filters, mixers, and combiners, in the FI-DAC structure, the output signal exhibits serious magnitude distortion. Hence, in this paper we establish an error model for an FI-DAC and propose a minimax method to design the magnitude-response compensation filter. Finally, the performance of the designed compensation filter was validated using a purpose-built experimental test bench.