Ultra-wideband Radar Signal Acquisition Technology

Ultra-wideband (UWB) radar has high range resolution, strong anti-latent capacity, and strong anti-jamming capacity because of broad bandwidth. UWB radar has been extensively studied in passive target identification, precise position, target imaging and discrimination. For the broad bandwidth, we need an analog-to-digital converter with wide instantaneous bandwidth, high speed, lower power and ease of use. But the parts are so hard to find because of the technology. So one can realize it by multi-channel data acquisition techniques. This paper studies the multi-channel architecture and analyzes the key techniques. The ultra-wideband data acquisition system is realized with frequency band dropping techniques, time delays techniques, and I and Q channels techniques. By analyzed the multi-channel techniques, a method in hardware or software can be realized to adjust the channel error. These will enhance the performance of the system.(1) To analyze the decomposition and construction filters in the frequency domain, and give the relation between the decomposition filters and the construction filters. If the decomposition filter is transformed from digital domain into analog domain, the frequency data acquisition structure is realized. This method can not only reduce the sampling clock, but also construct the signal correctly.(2) To analyze the time delays nonuniformity of time delays multi-channel with the theory of sampling nonuniformity. To analyze the nonuniformity of the analog-to-digital converter's DC reference voltage and the difference gain among the time delays multi-channels. By analyzed the time delays multi-channel techniques, a method in hardware or software can be realized to adjust the channel error.(3) To analyze the influence of the image signal that is caused by imbalance of amplitude and phase of I, Q channel in the data acquisition system. The error is calibrated on the following signal processing. To analyze and calibrate the DC reference voltage between I, Q channel.in(4) To realize the hardware design of UWB signal acquisition, design the interface between the AD board and the computer, and simulate the data acquisition system.