Research And Design Of Phased Focal Plane Array Unit Antenna For Wide Field Radio Telescope

Radio telescopes realize the study of pulsars,rapid electromagnetic bursts and the structure of the early universe by observing the amount of electromagnetic fields from space.The research and design of radio telescopes have greatly promoted the development of radio astronomy.Currently,radio telescopes based on phased array feeds are becoming research hotspots due to their excellent beam performance.Enlarging the element spacing of the phase-controlled focal plane array of the radio telescope can increase the field of view,but at the same time the system sensitivity and aperture efficiency will also decrease.When the distance between the array elements increases to a certain extent,the system field of view will also appear discontinuous.This paper intends to improve this problem through the design of the unit antenna.This article first introduces the simulation calculation program,and uses the dipole antenna and the ideal aperture surface.Through the comparison of the analytical model and the HFSS model,the correctness of the calculation program is verified,and it is used for the subsequent antenna unit design and radio telescope system.Performance optimization provides technical support.Then,using the sky survey velocity(SSFo M)as the index,the aperture simulation antenna unit on the infinite ideal conductive plane is used to simulate and analyze the relationship between the ideal aperture surface of different sizes and the system performance under different f/D conditions.The simulation results show that: choosing an antenna with good antenna pattern and proper 3d B beam width as the focal plane array unit can effectively improve the system's performance such as sky survey speed,sensitivity,aperture efficiency,and optimal array element spacing.The design of a Yagi antenna working at 1.4GHz verifies the correctness of the conclusion of the ideal aperture surface.Finally,an electromagnetic dipole antenna loaded with left-hand material is designed.When f/D=0.7 and1,the optimal element spacing of the electromagnetic dipole antenna can reach 0.75? and0.83? respectively.And compared with the performance of the Green Bank Telescope(GBT),the results show that the designed electromagnetic dipole antenna has improved sky survey speed(SSFo M)performance,sensitivity performance,and aperture efficiency compared with the GBT currently in use.The feasibility of using it as a focal plane array element antenna of a large field of view radio telescope.Finally,the dual-polarization design of the electromagnetic dipole antenna is realized.