Research And Design Of Wireless Video Receiver System

With the rapid development of wireless communication and the ever larger market, the data amount of real-time images has been increasing. Wireless RF has been widely used for its signal of good quality and little interference. It can transform larger information and there is not much interference from other signals because of its high carrier frequency, fast transformation rate and short wavelength. This paper describes the research and design of receiving system for wireless video with 5.8GHz frequency-band.The function and design demand of video receiving system is researched in detail in this paper. First, the key technical indexes of video receiver are described and we also give the overall layout by overall circuit planning and theory analysis to videos. The modules used in circuits are also analyzed and designed. Second, the development and basics of frequency synthesizers are introduced, the implement scheme is selected by comparing the two schemes of frequency synthesizer, and then the key apparatuses are selected and the power divider is designed. After that, we analyze the effect of loop filter to circuits. Third, the function of filter is introduced, lowpass filter and bandpass filter of image limit are designed, and then the filters are processed. After comparison and analysis to results of test and simulation, we find that the structure of filter is compacted and its performance is good, which can meet the demand of system.Finally, this paper introduces the theory of gain auto control, designs the gain control of IF signal after joint mixing by AGC circuit, adjusts the dynamic receiving range, and then makes and tests gain-variable amplifier. The test result can satisfy the system demand, meet the signal demodulation requirement and the receiving system is stable.