Analysis And Design Of Conformal Frequency Reconfigurable Wideband Antenna Based On Carrier Platform

Conformal antennas have become a hot topic in the field of antenna research due to their ability to meet the requirements of antenna operation without changing the shape structure and aerodynamics properties of high-speed moving carriers.However,with the continuous development and progress of military communication and countermeasures technology,high-speed moving carriers are facing the threat of enemy electromagnetic interference,which affects their battlefield survival ability.Frequency reconfigurable antennas can flexibly switch between multiple frequency bands,which can improve the carrier’s anti-interference ability and reduce electromagnetic compatibility issues on the carrier platform.On the basis of existing reconfigurable research,this article focuses on broadband frequency reconfigurable conformal antennas,miniaturized frequency reconfigurable conformal antennas,and multiple characteristic hybrid reconfigurable array antennas.The specific research content is as follows:（1）In response to the current problems of insufficient tuning range and large gain fluctuations in frequency reconfigurable antennas,this article combines the tuning method of PIN diodes and varactor diodes to design high and low frequency directional bands for diode conduction and disconnection.In the planar state,the gain fluctuation in the band is less than 1.2 d Bi.Antenna conformal to curvature radius R>0.5λThe surface of the dielectric cylindrical carrier can maintain a stable radiation pattern within the frequency tuning range,and the gain fluctuation is less than 1.9 d Bi.This antenna has the advantages of simple structure,low profile,and wide adjustable range.（2）In order to solve the problems of cross polarization rise,large number of controllable elements required and worsening impedance matching of existing miniaturized frequency reconfigurable antenna,this thesis etched coupling slots on the octagon patch antenna,and realized the miniaturization of frequency reconfigurable antenna by using capacitive load effect.The resonant frequency S₁₁<-20d B in each state,and the electric field distribution on the patch after introducing coupling slots is more symmetrical,Effectively suppressed the uplift of cross polarization.By forming a uniform linear array along the direction of the metal conical carrier bus,the antenna can still maintain a low cross polarization value within the±30°scanning range.This antenna has the advantages of simple structure,less use of lumped components,and low cross polarization level.（3）In order to solve the problems of insufficient reconstruction states,poor reliability and difficult independent reconstruction among parameters in multi-parameter composite reconfigurable antenna,the frequency,polarization and direction pattern reconfigurable antenna based on varactor diode and PIN diode was designed to verify the principle of directional pattern reconstruction.In order to improve control reliability and reduce testing cost,a reconfigurable array antenna with digital control is designed.The antenna can realize four frequency bands and four polarization states.In the circular polarization mode,it has five kinds of directional pattern which can be adjusted.In the linear polarization mode,it has the normal direction pattern,which can realize 48 kinds of working states.The antenna has the advantages of abundant reconstruction states,high control reliability and independent reconstruction among parameters.