The Analysis And Design Of X Band FMCW Radar RF Front-end

With the development of electronic technology, radar is widely used in various fields such as military and civilian, and different systems of radar are derived. Frequency modulation continuous wave(FMCW) radar, with its simple structure, high resolution, low transmission power, miniaturization, lightweight, simple algorithm and easy integration, has been more and more widely used. The most typical application of FMCW radar in civilian affairs is automobile anti-collision radar, it can rapidly detecting target in close range and warning of potential collisions, offering the driver enough reaction time to respond and avoiding many potential safety hazard. This thesis presents the implementation of an X band(9.8GHz-10GHz) with 200 MHz sweep bandwidth of FMCW radar RF front-end.This thesis describes the development process of FMCW radar at first, then introduces the principle of its ranging and velocity measurement. And when compared to other radars such as continuous wave(CW) radar and pulse radar(PR) radar, FMCW radar’s advantages and disadvantages are introduced. Then analyzes the indicators of X band FMCW radar in this subject. Basing on the FMCW radar demand indicators, key technologies and methods are presented.This thesis divides the entire RF front-end system into three parts: the linear frequency source, the transmitter and the receiver, and describes the design and implementation process respectively. When implementing the most critical part of the system, the linear frequency source, through the analysis and comparison of many schemes, we finally choose the structure of using the DDS+PLL out of loop mixing and multiplying to realize the linear frequency source. In the design of the receiver and transmitter, 3d B directional coupler are designed and simulated by using ADS software. Providing the details that need to pay attention and corresponding solving method of each module. At last, this thesis presents the schematic and PCB board and the pictures of the actual objects of each part. Also the shield cavity.The deficiencies, the improving method and expansibility of the entire RF front-end are introduced in the last chapter of this thesis.