Research On Test Technology Of High Speed ADV Frequency Domain Characteristics Based On DSP

With the development of modern hi-tech, especially the rapid development of microelectronics, computer and communication technology, analog to digital converter(ADC) technology has also been rapid development. As an important component of interface which connect the analog and the amount of data, analog to digital converter(ADC) push the door of analog leading to reality, open up the way of describe the real worldby the way of computer virtual world, therefore it is widely used in wireless communications, radar, software radio and video transmission and other fields, and is an important part of modern high-tech and information industry development. In practical applications of high-speed ADC, the actual performance of ADC chip can not achieve the rated performance due to deviations of ADC chip design or decline ofperformance affected by external factors, which led to malfunction of the circuit system. So it is necessary to test the performance of ADC chip.This paper researchesthe method offrequency-domain test on high-speed ADC, and introduces the key parameter of frequency characteristics and the problems encountered during the test of frequency characteristics. Forthe inherent spectrum leakage and fence effectof DFT / FFT in frequency characteristics testin the non-coherent sampling mode, the paper leads to the concept of windows and interpolated, summarizes the common methods of currentfrequency-domain windowing in studying FFT, and then leads to a new description method of window function---the algorithm frequency domain windowing by setting zeros. According to the actual demand, make use of frequency domain windowing by setting zeros algorithm and design a set of window function with small side-lobe peaks and fast side-lobe attenuation, and then analyze their test performance in frequency domain, and their advantage in suppressing spectral leakage in compared with the traditionalwindow function; For the hurdle effectin frequency domain analysis,describe common interpolation algorithm and introduces a new interpolation algorithm---the algorithm of fitting coefficient interpolationfrom window function spectrum,analyze thetest performance of this method in frequency domain, and its advantageat field of high speed ADC in compared with the traditional interpolation algorithm; make use of new designed window function to fitting coefficient interpolationfrom window function spectrum to achieve spectrum correctionand weak signal detection in frequency-domain test on high-speed ADC.The final research results will be tested onthe platform of PXI vector signal source project. Complete the test of high speed ADC frequency domain and the algorithm of frequency domain windowing by setting zerosand the algorithm of fitting coefficient interpolationfrom window function spectrumon DSP. And then complete the detection of weak signal on the basis of this. The test data will be analyzed by CCS software to get the parameters of frequency domain characteristic. The analysis shows the windows designed by the algorithm of frequency domain windowing from setting zeros can effectively improve the detection of weak signal. The effect is a little worse than the theoretical results.