Research And Design Of Planar Phased Array Antennas

Phased array antennas are not new and have been used in military radar for decades.Due to its high cost,phased array technology has not been widely used in the past.With the advancement of semiconductor technology,more cost-effective phased array schemes have been proposed,and this technology has gradually been applied to other fields,such as satellite communication represented by Starlink.Due to their fast,flexible and accurate beam scanning capabilities compared with traditional mechanical scanning antenna,electrical scanning antennas represented by phase scanning antenna have been widely used in military/aerospace fields in the past,and the research on phased array antennas has made great progress in the past few decades.This theis focuses on array antennas to microstrip patch array antennas and waveguide slot array antennas,and the main contents are as follows:1.A 3×3 microstrip patch array was designed.Firstly,a patch unit antenna was designed by increasing the thickness of the substrate,low dielectric constant substrate material and slot coupling feeding,and then a one-to-three unequal distribution feeding network was designed by Taylor weighting,using two one-point two-way power divider cascading,and the middle two ports were combined to achieve a large power ratio,and was arrayed with the antenna unit.Finally,based on the subarray of 1×3,the unequal feed network is also added to form a 3×3 array,within the working frequency band of16GHz～16.4GHz,the VSWR is within 1.4,the overall gain is 15.9d Bi,and the average secondary lobe electricity of the two main planes is less than-16 d B.2.A traveling wave slotted waveguide array antenna was designed.First,a singleridge waveguide is used to reduce the elevation waveguide spacing to meet the scanning requirements.A coaxial-waveguide converter is then designed to feed the waveguide,using a multi-stage stepped impedance converter to adjust the waveguide impedance to achieve matching.Then,according to the polarization requirements,the slot parameters were extracted in Ansys HFSS,that is,the relationship between slot conductance and center offset and slot length when resonance.The slot excitation amplitude is synthesized by Taylor synthesis,and the slot admittance distribution under the required aperture distribution is completed using the traveling wave approximation method.Slot antenna modeling can be completed by obtaining the slot center offset and slot length according to the admittance distribution.The simulation results of optimized antenna shows good return loss,gain and side lobe level,and finally the antenna is processed and tested,and the test results shows that the gain of the antenna is about 22 d Bi,the VSWR in the working frequency band is basically within 1.3,the side lobe level is about-22 d B,which are not much different from the simulation.