The design of receiver for ultra wideband automotive anti-collision radar
|School||University of Electronic Science and Technology|
|Keywords||equivalent time sampling UWB sampling gate DDS radar data processing|
Due to the increase of the amount of vehicles, the rate of car accident is rising. It is very significant to research the anti-collision radar. According to the12th five-year plan of China, government has taken the automobile intelligent electronic into the plans and the research on the anti-crashing radar system is going far, and created an excellent platform for research.To achieve high sensitivity, high sampling rate and high input bandwidth ADCs(Analog-to-Digital Converter) are strongly required, while most of them are designed in the foreign companies, which cause high cost, still, it has a problem of high data transfer rate. This design focus on the problem of low sampling rate and low input bandwidth for low cost ADC, and a UWB sampling gate base on equivalent time sampling is designed, which has an equivalent theory bandwidth of6.35GHz and equivalent sampling rate of20Gsa/s.This paper is formulated around the deceleration principle of the UWB(Ultra wide band) sampling circuit, also, two methods of designing the circuit are presented. According to the simulation of the circuit with ADS(Agilent Advanced Design System), the sampling bandwidth and the rate voltage conversion efficiency is calculated. The circuit based on SPD(Sampling Phase Detector) is tested, and the feasibility of the circuit is improved. Step frequency signal is essential for equivalent-time sampling. The step frequency signal is formulated by circuit based on DDS(Direct Digital Synthesizer). To minimize the jitter, a differential filter is designed. The step frequency signal forming circuit was proved of good performance. Finally, we process and display the radar data. After filtering, B-scan imagining, median filtering, direct wave filtering, we can locate the obstacle precisely.