Research On Wideband Sparse Phased Array Optimization Design And Array Element Phase Patterns Measurement And Correction

Wideband antenna arrays are widely used in wireless systems due to their advantages of large bandwidth,which can meet the needs of transmitting or receiving signals at different frequencies.However,the electrical size spacing,impedance,and radiation performance of wideband antenna arrays may vary drastically with frequency.Therefore,selecting appropriate array elements,array structures,and synthesis methods to design and optimize wideband antenna arrays has considerable research value and challenges.In addition,ensuring the consistency of the phase response of each array element is crucial in array antenna testing,which determines the measurement accuracy of devices such as interferometers.This thesis mainly focuses on the research of wideband array element and array design,cross-polarization level optimization design,and calibration of array element phase response consistency.The main research contents of this thesis are as follows:1.A miniaturized Archimedean planar spiral antenna was designed.The antenna has the following design features:(1)sinusoidal loading is applied to two Archimedean spiral lines,and lumped resistors are loaded at the end to extend the current path and improve low-frequency performance?(2)a special-shaped slot consisting of a combination of a cross slot and a circular slot is loaded in the back cavity,which can be regarded as a circularly polarized antenna and can improve axial ratio?(3)absorbing material is filled below the special-shaped slot to absorb backward radiation.Then,the antenna is used as array element,and the wideband sparse array layout method is applied to generate a wideband sparse layout.The resulting array exhibits the characteristics of large bandwidth.2.A random 2-bit state rotation cross-polarization suppression technique is proposed.Based on the designed cross-dipole antenna element,the right and left circularly polarized active element patterns of the circularly polarized array element are extracted.The element patterns are rotated around the geometric center of the element,and the corresponding phase is compensated after rotation.Then,all the active element patterns are added to obtain the rotated array pattern.The optimal rotation angle is selected in the optimization process to obtain the best circular polarization performance of the wideband sparse array.The simulation and measured results of the 140-element circularly polarized array obtained using this method exhibit good performance.3.A measurement and calibration method for the consistency of the phase patterns of the array antenna based on path difference correction is used to correct the phase patterns consistency of the antenna array element with different spacing configurations.This method can measure and correct the phase patterns of the array antenna element without moving the array in the far-field antenna anechoic chamber.The path difference between the phase center of the array antenna element and the rotation center of the platform is calculated to compensate for the phase patterns of each element.The root mean square error is used to evaluate the consistency of the phase patterns of different elements in the array antenna.Two arrays with different spacing configurations were processed and measured,and the calibrated phase patterns showed good consistency,verifying the effectiveness of this method.