Research On Techniques Of Waveform Generation Based On Time-Interleaved DAC

The technology of digital waveform synthesis has been widely used in many fields, because of its distinct advantages in frequency stability, resolution, switching speed and strict coherence. With the development of technology, the signal bandwidth of radar and communication system is constantly increasing, which restricts the application of digital waveform synthesis. To solve this problem, the Time-Interleaved Digital-to-Analog Converter(TI-DAC) structure becomes an important research direction. With several DACs working on time-interleaved mode, TI-DAC structure can multiply the sampling frequency and bandwidth of system. In this paper, the TI-DAC technology is thoroughly studied. The basic principle, error analysis, error detection and correction are mainly analyzed, and the main works are as follows.1. The basic principle of TI-DAC is analyzed and proved by system modeling and formula derivation. The particular effect of DAC’s zero-order hold character is deeply studied and two methods, differentially encoding and Return-to-Zero DAC, are proposed to compensate for this effect. The performance of the methods is studied and simulated.2. A thorough research on systematical error of TI-DAC is conducted. With the analysis and model of error source, the formula derivation of phase error and amplitude error is completed. The simulation for effect of systematical error on signal spectrum and pulse-compression performance is conducted.3. A new method, which is based on the Signal-to-Image ratio, is proposed to evaluate the error in the TI-DAC system. Based on that, a complete block diagram of TI-DAC structure with error correction is put forward, which provides guidance to the engineering application.