The Analysis And Design On Feeding Network Of P Band Monopulse Antenna Array

This dissertation analyzes and designs feeding network of monopulse antenna array at P band, which applies to 3′16 Yagi antenna array.A brief introduction to the method of analyzing Yagi antenna is given at first, then the structure of Yagi antenna array. This dissertation calculates the distribution on the aperture of Yagi antenna array, by the way of Taylor Synthesis method. The theoretical sum-difference antenna pattern of azimuth plane and elevation plane is finally achieved by programming with the distribution on the aperture.Then, this dissertation continues to introduce feeding network, including relevant theories such as feeding network form、the performance of strip-line、theory of power divider, as well as theory of monopulse technology. In addition, we simulates Wilkinson power divider with and without isolation resistance for a further comparing of the simulation results. Irrational design will increase the size and volume of the feeding network at P band, thus increasing the difficulty of equipment and use. After careful analysis, this dissertation separates feeding network into five power divider networks, four 1-to-12 power dividers and one sum-difference power divider network. Then according to the theory of power divider design, this dissertation focuses on designing air strip-line power divider without isolation resistance. Afterwards, a novel power divider, which is directly distributed from one to three, is designed, concatenated with the four output ports of an already-designed 1-to-4 power divider and forms a network of 1-to-12 power divider in order to feed four relevant units of the three rows antenna array. Sum-difference network is designed in turn by using a simple-structured hybrid ring coupler. Simulation results meet the design requirements. In the process of the whole feeding network simulation, this dissertation finally joints the 5 designed power networks together by Designer. The input VSWR is less than 1.4, the amplitudes of S parameters of output ports are less than 0.2dB, and phase difference is less than 10°, isolation of sum and difference port is over 30 dB. Then this dissertation simulates antenna pattern for the purpose of comparing with theory pattern.This dissertation ends with related actual tests of every power divider network,imitates antenna array pattern in comparison with simulation results and proves the feasibility of feeding network design of this dissertation.