Research On Strong Mutual Coupling Array Antenna Based On New Impedance Matching Method

At present,the array antenna is widely used in communication system,with the communication information exchange more and more closely,its communication system has higher requirements for the antenna at the front end of the system,the ultra-wideband array antenna has its unique advantages to get wide attention,the ultra-wideband array with good performance should not only have a broadband radiation structure,but also have a good ultra-wideband feed circuit for matching,so in the antenna design process,in addition to the antenna itself Therefore,in the antenna design process,besides the special broadband radiation layer structure,the feed structure with ultra-broadband matching effect is very important,and its main role is to realize the conversion and impedance matching between the unbalanced end of the feed coaxial line and the balanced radiator,and then complete the high-efficiency energy transfer in the broadband.The thesis is based on a new impedance matching method for the study of strongly mutually coupled array antennas,and completes the whole simulation,fabrication and testing process from the design of ultra-wideband antenna units to array formation.The comparative analysis of the simulated data and physical test data shows that the relative bandwidth reaches 2.5 octave,the effective bandwidth is 4GHz?10GHz,the C-band and X-band coverage is basically achieved,and the scanning blind spot is removed within the scanning angle of ±60°.The main innovative work includes the following parts.1.Proposed the combination of Marchand balun and hyperbolic microstrip balun to match the antenna high resistance value and high reactance value to 50? and 0? respectively,providing a new idea for impedance matching of high impedance antennas.In which Marchand balun and hyperbolic microstrip balun are designed as vertical parallel structures,integrating these two different baluns in a finite cell size.2.By studying the effect of the net current generated by the unbalanced Barron feed on the radiation gain,it is proposed to use the metal isolation wall to change the field distribution of the net current,which will completely eliminate the effect of the common mode current on the antenna radiation capability throughout the scanning angle,and the results are confirmed by HFSS simulation.3.The performance of the designed linked-arm dipole array antenna is improved compared with the conventional array antenna,which confirms that the linked-arm dipole array can make the array antenna obtain a wider frequency band.