Large Dynamic And High Plus Radar Receiver Project

Radar receiver is an important part of the radar system , the main function is to amplified , change frequency and filter and to digital the signal receive from the radar antenna , while suppressant the interference and clutter from the outside , and aircraft noise inside , so that the signal can be maintained as much target information as possible for further signal processing and data processing . As wireless communication technology, especially the modern modulation system and the developing software radio technology with the increasing wireless spectrum , the receiver in the design and implementation is of a growing trend in high-performance and highly-integrated direction. There proposed more and more stringent requirements to the performance indicators about the receiver such as linearity, dynamic range, sensitivity, anti-interference ability, adaptability. These requirements also contributed to the continuous progress of the receiver which require it to under the premise of ensuring signal detection ability (ie high sensitivity) of the premise, as far as possible to improve the receiver linearity, minimize the signal distortion and lowest the error rate . Broaden the dynamic range of the receive as possible can greaten fitness and strengthen anti-interference ability of the receiver.The input signal of radar receiver often in a very short time interval swings, or simultaneously with a variety of very different signal strength. If a general linear amplifiers handled these signals ,which be input a large-signal ,it cause receiver overload and does not work. In order to properly receive these signals , instantaneous dynamic range compression device must be used. At the same time in order to ensure dynamic range and system bandwidth of the A/D converter, it requirements IF circuit can provide a dynamic range large enough , high sensitivity and bandwidth.In this paper, the significance of the research and the future direction of the large dynamic high-gain radar receiver are put forward. In this paper , there describes four common receiver structure of the current system, and finally choose superheterodyne receiver system by analysing the advantages and disadvantages and System Requirements . At the same time , the key indicator of the receiver has been analyzed. The design of RF front-end program are described, receiver design goals are proposed, a detailed system of indicators requirements and distribution of specific indicators about function circuit of each unit are given . The whole cascade system has been detailed analysed. Also described in detail selected successive detection logarithmic amplifier features as logarithmic IF amplifier, which enables a 70dB dynamic range logarithmic IF amplifier design, plate making, and testing.